Catalyst for the production of nitriles

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a catalyst for the production of nitriles. More particularly, it relates to an improved catalyst for the production of nitriles from alkanes as starting material.
2. Discussion of Background
Nitriles such as acrylonitrile and methacrylonitrile have been industrially produced as important intermediates for the preparation of fibers, synthetic resins, synthetic rubbers and the like. The most popular method for producing such nitriles is to subject an olefin such as propylene or isobutene to a catalytic reaction with ammonia and oxygen in the presence of a catalyst in a gaseous phase at a high temperature.
On the other hand, in view of the price difference between propane and propylene or between isobutane and isobutene, an attention has been drawn to developing a method for producing acrylonitrile or methacrylonitrile by a so-called ammoxidation reaction method wherein a lower alkane such as propane or isobutane is used as starting material, and it is catalytically reacted with ammonia and oxygen in a gaseous phase in the presence of a catalyst.
For example, there have been reports on a Mo--Bi--P--O catalyst (Japanese Unexamined Patent Publication No. 16887/1973), a V--Sb--O catalyst (Japanese Unexamined Patent Publication No. 33783/1972, Japanese Examined Patent Publication No. 23016/1975 and Japanese Unexamined Patent Publication No. 268668/1989), a Sb--U--V--Ni--O catalyst (Japanese Examined Patent Publication No. 14371/1972), a Sb--Sn--O catalyst (Japanese Examined Patent Publication No. 28940/1975), a V--Sb--W--P--O catalyst (Japanese Unexamined Patent Publication No. 95439/1990), a catalyst obtained by mechanically mixing a V--Sb--W--O oxide and a Bi--Ce--Mo--W--O oxide (Japanese Unexamined Patent Publication No. 38051/1989). Further, the present inventors have reported on a Mo--V--Te--Nb--O catalyst (Japanese Unexamined Patent Publication No. 257/1990 and U.S. Pat. No. 5,049,692).
However, none of these methods is fully satisfactory in the yield of the intended nitriles. In order to improve the yield of nitriles, it has been proposed to add a small amount of an organic halide, an inorganic halide or a sulfur compound, or to add water to the reaction system. However, the former three methods have a problem of possible corrosion of the reaction apparatus, while the latter water-adding method has a problem of formation of by-products by side reactions or a problem of their treatment. Thus, each method has a practical problem for industrial application.
Further, methods using the conventional catalysts other than the Mo--V--Te--Nb--O catalyst reported by the present inventors, usually require a very high reaction temperature at a level of 500.degree. C. or higher. Therefore, such methods are disadvantageous in terms of reactor material, production cost, etc.
SUMMARY OF THE INVENTION
The present inventors have conducted extensive researches on the method for producing a nitrile by using an alkane as starting material. As a result, they have found it possible to produce a desired nitrile in remarkably better yield than conventional methods at a relatively low temperature of a level of from 400.degree. to 450.degree. C. without adding a halide or water to the reaction system, by subjecting the alkane and ammonia in the gaseous state to catalytic oxidation in the presence of a catalyst comprising molybdenum (Mo), vanadium (V), tellurium (Te) and certain types of metals and having a certain specific crystal structure. The present invention have been accomplished on the basis of this discovery.
Thus, the present invention provides a catalyst for the production of a nitrile from an alkane, which satisfies the following conditions 1 and 2:
1 the catalyst is represented by the empirical formula:
MO.sub.a V.sub.b Te.sub.c X.sub.x O.sub.n ( 1)
wherein X is at least one element selected from the group consisting of Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ni, Pd, Pt, Sb, Bi, B and Ce,
when a=1,
b=0.01 to 1.0,
c=0.01 to 1.0,
x=0.01 to 1.0,
and n is a number such that the total valency of the metal elements is satisfied; and
2 the catalyst has X-ray diffraction peaks at the following angles of 2.theta. in its X-ray diffraction pattern:
Diffraction
angles of 2.theta. (.degree.)
22.1.+-.0.3
28.2.+-.0.3
36.2.+-.0.3
45.2.+-.0.3
50.0.+-.0.3.
Further, the present invention provides a process for producing such a catalyst, which comprises drying an aqueous solution containing compounds of molybdenum, vanadium and tellurium and a compound of at least one element selected from the group consisting of niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, antimony, bismuth, boron and cerium, and calcining the dried product in the absence of oxygen; which comprises drying an aqueous solution containing compounds of molybdenum, vanadium and tellurium and a compound of at least one element selected from the group consisting of niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, antimony, bismuth, boron and cerium, calcining the dried product in the absence of oxygen to obtain a complex oxide, adding to the complex oxide an oxide containing at least one element selected from the group consisting of antimony, bismuth, cerium and boron, and calcining the mixture; or which comprises a drying an aqueous solution containing compounds of molybdenum, vanadium and tellurium and a compound of at least one element selected from the group consisting of niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, antimony, bismuth, boron and cerium, calcining the dried product in the absence of oxygen to obtain a complex oxide, adding to the complex oxide an organic compound containing at least one element selected from the group consisting of antimony, bismuth, cerium and boron, and calcining the mixture.
Furthermore, the present invention provides a process for producing a catalyst, which comprises adding a compound of at least one element selected from the group consisting of antimony, bismuth, cerium, boron, manganese, chromium, gallium, germanium, yttrium and lead to a complex oxide which is represented by the empirical formula:
Mo.sub.a V.sub.b Te.sub.c X.sub.x O.sub.n ( 1)
wherein X is at least one element selected from the group consisting of Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ni, Pd, Pt, Sb, Bi, B and Ce,
when a=1,
b=0.01 to 1.0,
c=0.01 to 1.0,
x=0.01 to 1.0,
and n is a number such that the total valency of the metal elements is satisfied, and which has X-ray diffraction peaks at the following angles of 2.theta. in its X-ray diffraction pattern:
Diffraction
angles of 2.theta. (.degree.)
22.1.+-.0.3
28.2.+-.0.3
36.2.+-.0.3
45.2.+-.0.3
50.0.+-.0.3,
to obtain a mixture, and calcining the mixture.

BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 shows the powder X-ray diffraction pattern of the complex oxide obtained in Example 1.
FIG. 2 shows the powder X-ray diffraction pattern of the complex oxide obtained in Comparative Example 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the present invention will be described in detail with reference to the preferred embodiments.
The catalyst useful for the process of the present invention for producing a nitrile by reacting an alkane with ammonia by a gas phase catalytic oxidation reaction, has the above mentioned chracteristics 1 and 2.
The complex oxide having such a specific crystal structure can be prepared by the following method.
For example, in the case of Mo.sub.a V.sub.b Te.sub.c Nb.sub.x O.sub.n, added sequentially to an aqueous solution containing a predetermined amount of ammonium metavanadate, are an aqueous solution of telluric acid, an aqueous solution of ammonium niobium oxalate and an aqueous solution of ammonium paramolybdate in such amounts that the atomic ratios of the respective metal elements would fall in the specified ranges. Then, the mixture is dried by evaporation to dryness, a spray drying method or a vacuum drying method, and finally, the dried product is calcined to obtain the desired oxide. To efficiently conduct the calcination, the above dried product may be decomposed under heating at a temperature of from 150.degree. to 350.degree. C. in air or in an inert gas atmosphere such as nitrogen or argon, prior to the final calcination.
In the process for preparing the specific complex oxide to be used as the catalyst of the present invention, the calcination conditions are particularly important. For calcination treatment to prepare an ordinally oxide, it is most common to employ a method wherein calcination is conducted in an oxygen atmosphere. However, in the present invention, calcination is preferably conducted in an atmosphere substantially free from oxygen, for example, in an inert gas atmosphere such as nitrogen, argon or helium. Further, such a gas may contain a reducing gas such as hydrogen or a hydrocarbon, or steam. Otherwise, the calcination may be conducted under vacuum usually at a temperature of from 350.degree. to 700.degree. C., preferably from 400.degree. to 650.degree. C., usually for from 0.5 to 35 hours, preferably from 1 to 10 hours. At a temperature lower than this temperature range, formation of the above crystal structure presenting the high catalytic activities tends to be inadequate. On the other hand, if it exceeds the above temperature range, a part of the crystal structure is likely to be thermally decomposed, such being undesirable.
When the content of oxygen in the complex oxide thus obtained, is examined, for example, in the case of Mo.sub.1 V.sub.b Te.sub.c Nb.sub.x O.sub.n, the value of n is smaller than (3a+2.5b+3c+2.5x) which represents the value corresponding to the most highly oxidized state of Mo, V, Te and Nb, and it is at a level of from 80 to 97% thereof. Namely, the complex oxide having the specific structure to be used as the catalyst of the present invention corresponds to a complex oxide obtainable by calcining a dried product of the same starting materials under a usual oxidizing atmosphere except that the oxygen content is slightly smaller.
The catalyst of the present invention is a complex oxide of the above formula (1), wherein X is at least one element selected from the group as defined above. However, X is preferably Nb, Ta, W or Ti, particularly preferably Nb. Further, with respect to the coefficients in the formula (1), it is particularly preferred that when a=1, b=0.1 to 0.6, c=0.05 to 0.4, and x=0.01 to 0.6.
However, the complex oxide is not adequate as a catalyst for the reaction of the present invention if it merely satisfies the composition represented by the formula (1), and it is important that the complex oxide has a certain specific crystal structure.
An index showing that the complex oxide to be used as a catalyst of the present invention has the specific crystal structure, is the powder X-ray diffraction pattern. The X-ray diffraction pattern of the complex oxide is characterized in that it shows the following five main diffraction peaks at the specific diffraction angles of 2.theta. (as measured by using Cu--K.alpha.-rays as the X-ray source):
______________________________________Diffraction Center values of X-ray Relativeangles of 2.theta. (.degree.) lattice spacing (.ANG.) intensity______________________________________22.1 .+-. 0.3 4.02 10028.2 .+-. 0.3 3.16 20 to 15036.2 .+-. 0.3 2.48 5 to 6045.2 .+-. 0.3 2.00 2 to 4050.0 .+-. 0.3 1.82 2 to 40______________________________________
The intensities of X-ray diffraction peaks may differ depending upon the measuring conditions for each crystal. However, the relative intensities based on the peak intensity at 2.theta.=22.1.degree. being 100, are usually within the above identified ranges. In general, the peak intensities at 2.theta.=22.1.degree. and 28.2.degree. are higher than others. However, so long as the above identified five diffraction peaks are observed, there will be no change in the basic crystal structure even if there are some peaks observed in addition to the above five diffraction peaks, and such a complex oxide can be suitably used for the present invention.
Thus, it is totally unexpected and surprising that the complex oxide not only has the specific crystal structure but also provides remarkably high catalytic activities as compared with the conventional catalyst in the reaction to obtain a nitrile from an alkane as starting material.
Further, the materials for the above complex oxide are not limited to the ones described above. For example, V.sub.2 O.sub.5, V.sub.2 O.sub.3, VOCl.sub.3 or VCl.sub.4 may be used instead of ammonium metavanadate, and TeO.sub.2 may be used instead of telluric acid. Likewise, NbCl.sub.5, Nb.sub.2 O.sub.5 or niobic acid may be used instead of ammonium niobium oxalate, and MoO.sub.3 or MoCl.sub.5 may be used instead of ammonium paramolybdate.
The complex oxide of the formula (1) prepared in the manner as described above, has adequate catalytic activities by itself. However, in order to further improve the selectivity and yield of the nitrile, it is particularly preferred to use a catalyst having a certain specific oxide in corporated to the complex oxide. As such a specific oxide, it is possible to employ an oxide containing at least one member selected from the group consisting of antimony, bismuth, cerium, boron, manganese, chromium, gallium, germanium, yttrium and lead. An antimony oxide is particularly preferred.
The antimony oxide to be incorporated may, for example, be an antimony oxide such as Sb.sub.2 O.sub.3, Sb.sub.2 O.sub.4 or Sb.sub.2 O.sub.5, and it may otherwise be an oxide having a composition of e.g. SbO.sub.2.(Sb.sub.2 O.sub.4). These oxides may be used alone or in combination as a mixture of a plurality of them. Otherwise, it may be used in the form of a hydrate. Further, in some cases, it is possible to employ as a solid catalyst a substance prepared by incorporating an organic compound containing antimony, such as ammonium antimony tartarate or antimony oxalate to the complex oxide of the formula (1), followed by calcination. In this case, the organic compound containing antimony will be converted to antimony oxide by the calcination.
The bismuth oxide to be incorporated may, for example, be a bismuth oxide such as Bi.sub.2 O.sub.3 or Bi.sub.2 O.sub.4, and it may also be a hydrate such as Bi.sub.2 O.sub.4.2H.sub.2 O. These oxides may be used alone or in combination as a mixture of a plurality of them. In some cases, a salt of an organic or inorganic acid or a hydroxide containing bismuth, such as bismuth hydroxide, bismuth nitrate, bismuth nitrate oxide or bismuth acetate may be added to the complex oxide of the formula (1), followed by calcination, and the substance thereby obtained can be used as a solid catalyst. In this case, the salt or the hydroxide containing bismuth will be converted to bismuth oxide by the calcination.
The cerium oxide may, for example, be a cerium oxide such as Ce.sub.2 O.sub.3 or CeO.sub.2. These oxides may be used alone or in combination as a mixture of a plurality of them. In some cases, a salt of an organic or inorganic acid, or a hydroxide containing cerium, such as cerium nitrate, cerium hydroxide, cerium oxalate or cerium acetate, may be added to the complex oxide of the formula (1), followed by calcination, and the product of the calcination can be used as a solid catalyst. In this case, the salt or the hydroxide containing cerium will be converted to cerium oxide by the calcination. The boron oxide is usually B.sub.2 O.sub.3. However, a boric acid or a boric acid ester, such as orthoboric acid, metaboric acid, ethyl borate or propyl borate, may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In such a case, the boric acid or the boric acid ester is believed to be converted to boron oxide by the calcination.
The manganese oxide to be incorporated may, for example, be MnO, Mn.sub.3 O.sub.4, Mn.sub.2 O.sub.3, MnO.sub.2, Mn.sub.2 O or Mn.sub.8 O.sub.7. These oxides may be used alone or in combination as a mixture of a plurality of them, and they may be used in the form of a hydrate. In some cases, a compound containing manganese, such as MnCl.sub.2, MnCO.sub.3 or MnC.sub.2 O.sub.4, may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In this case, the manganese-containing compound will be converted to manganese oxide by calcination.
The chromium oxide to be incorporated may, for example, be CrO, Cr.sub.2 O or CrO.sub.3. These oxides may be used alone or in combination as a mixture of a plurality of them, and they may be used in the form of a hydrate. In some cases, a compound containing chromium, such as CrCl.sub.2, CrCl.sub.3 or Cr(NO).sub.3 may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In such a case, the chromium-containing compound will be converted to chromium oxide by calcination.
The gallium oxide may, for example, be Ga.sub.2 O or Ga.sub.2 O.sub.3. These oxides may be used alone or in combination as a mixture of a plurality of them, and they may be used in the form of a hydrate. In some cases, a compound containing gallium, such as GaCl.sub.2 or GaCl.sub.3, may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In this case, the gallium-containing compound will be converted to gallium oxide by calcination.
The germanium oxide may, for example, be Ge.sub.2 O or Ge.sub.2 O.sub.3. These oxides may be used alone or in combination as a mixture of a plurality of them, and they may be used in the form of a hydrate. In some cases, a compound containing germanium, such as GeCl.sub.2 or GeCl.sub.4, may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In this case, the germanium-containing compound will be converted to germanium oxide by calcination.
The yttrium oxide to be incorporated is usually Y.sub.2 O.sub.3, but may be used in the form of a hydrate. Further, in some cases, a compound containing yttrium, such as YCl.sub.2, Y(NO).sub.3 or Y.sub.2 (C.sub.2 O.sub.4).sub.3, may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In this case, the yttrium-containing compound will be converted to yttrium oxide by calcination.
The lead oxide to be incorporated may, for example, be Pb.sub.2 O, PbO, Pb.sub.3 O.sub.4, Pb.sub.2 O.sub.3, PbO.sub.2. These oxides may be used alone or in combination as a mixture of a plurality of them, and they may be used in the form of a hydrate. In some cases, a compound containing lead, such as Pb(NO).sub.3, PbOH, PbCO.sub.3 or PbC.sub.2 O.sub.4, may be added to the complex oxide of the formula (1), followed by calcination, and the calcined product can be used as a solid catalyst. In this case, the lead compound will be converted to lead oxide by calcination.
As a method for incorporating the above mentioned specific oxide to the complex oxide, it is advisable to pulverize and mix both materials so that the contact of the specific oxide with the complex oxide can be effectively done. The amount of the specific oxide to the complex oxide is usually from 0.0001 to 0.2, preferably from 0.001 to 0.05 by the weight ratio to the complex oxide. After the addition, the mixture may be used as it is for the reaction to produce a nitrile from an alkane. However, in order to effectively obtain the effects of the addition of the specific oxide, it is preferred to calcine the mixture again at a temperature of from 300.degree. to 650.degree. C., preferably from 350.degree. to 600.degree. C., usually for from 0.5 to 30 hours, preferably from 1 to 10 hours. The atmosphere for calcination is not particularly limited, but it is usually preferred to employ an inert gas atmosphere such as nitrogen, argon or helium, and the inert gas may further contain a reducing gas such as hydrogen, ammonia or a hydrocarbon, or steam. Otherwise, the calcination may be conducted under vacuum.
Even if the specific oxide is added to the complex oxide, followed by mixing and calcination, the X-ray diffraction pattern of the obtained product is substantially the same as that of the complex oxide before the addition of the specific oxide, and there is no substantial change observed in the crystal structure.
The above catalyst may be used alone. However, it may be used together with a conventional carrier such as silica, alumina, titania, aluminosilicate or diatomaceous earth. Further, depending upon the scale or system of the reaction, it may be molded into a proper shape and particle size.
According to the present invention, a nitrile can be produced efficiently by subjecting an alkane to a gas phase catalytic oxidation reaction with ammonia in the presence of the above catalyst.
In the present invention, the alkane as the starting material is not particularly limited and may, for example, be methane, ethane, propane, butane, isobutane, pentane, hexane, heptane or cyclohexane. However, in view of the industrial application of nitriles to be produced, it is particularly preferred to employ a lower alkane having from 1 to 4 carbon atoms, particularly propane or isobutane.
The detailed mechanism of the oxidation reaction of the present invention is not clearly understood. However, the oxidation reaction is conducted by the oxygen atoms present in the above complex oxide or by the molecular oxygen present in the feed gas. When molecular oxygen is incorporated in the feed gas, the oxygen may be pure oxygen gas. However, since the purity is not required, it is usually economical to use an oxygen-containing gas such as air.
As the feed gas, it is common to use a gas mixture comprising an alkane, ammonia and an oxygen-containing gas. However, a gas mixture comprising an alkane and ammonia, and an oxygen-containing gas may be supplied alternately.
When the gas phase catalytic reaction is conducted using an alkane and ammonia substantially free from molecular oxygen, as the feed gas, it is advisable to employ a method wherein a part of the catalyst is properly withdrawn and sent to an oxidation regenerator for regeneration, and the regenerated catalyst is returned to the reaction zone. As a method for regenerating the catalyst, a method may be mentioned wherein an oxidizing gas such as oxygen, air or nitrogen monoxide is permitted to flow through the catalyst in the regenerator usually at a temperature of from 300.degree. to 600.degree. C.
The present invention will be described in further detail with respect to a case where propane is used as the alkane and air is used as the oxygen source. The proportion of air to be supplied for the reaction is important with respect to the selectivity for the resulting acrylonitrile. Namely, high selectivity for acrylonitrile is obtained when air is supplied within a range of at most 25 mols, particularly from 1 to 15 mols, per mol of propane. The proportion of ammonia to be supplied for the reaction is preferably within a range of from 0.2 to 5 mols, particularly from 0.5 to 3 mols, per mol of propane. This reaction may usually be conducted under atmospheric pressure, but may be conducted under a slightly increased pressure or a slightly reduced pressure. With respect to other alkanes, the composition of the feed gas can be selected in accordance with the conditions for propane.
The process of the present invention can be conducted at a temperature of e.g. from 340.degree. to 480.degree. C., which is lower than the temperature for conventional ammoxidation of alkanes. More preferably, the temperature is from 400.degree. to 450.degree. C. The gas space velocity SV in the gas phase reaction is usually within a range of from 100 to 10,000 hr.sup.-1 preferably from 300 to 2,000 hr.sup.-1. As a diluent gas for adjusting the space velocity and the oxygen partial pressure, an inert gas such as nitrogen, argon or helium can be employed. When ammoxidation of propane is conducted by the method of the present invention, in addition to acrylonitrile, carbon monooxide, carbon dioxide, acetonitrile, hydrocyanic acid, acrolein, etc. will form as by-products, but their amounts are very small.

Now, the present invention will be described in further detail with reference to Examples and Comparative Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples.
In the following Examples and Comparative Examples, the conversion (%), the selectivity (%) and the yield (%) are shown by the following formulas, respectively: ##EQU1##
EXAMPLE 1
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n was prepared as follows.
In 117 ml of warm water, 4.21 g of ammonium metavanadate was dissolved, and 4.13 g of telluric acid and 15.89 g of ammonium paramolybdate were sequentially added thereto to obtain a uniform aqueous solution. Further, 3.99 g of ammonium niobium oxalate was dissolved in 17.9 ml of water and added thereto to obtain a slurry. The obtained slurry was evaporated to dryness at about 150.degree. C. to obtain a dried product.
This dried product was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at a temperature of 620.degree. C. for two hours. FIG. 1 shows a chart of the peaks of the powder X-ray diffraction pattern of the complex oxide thus obtained, and Table 1 shows the relative intensities of the main X-ray diffraction peaks.
Further, the oxygen content in the complex oxide was measured by an oxygen analyzer and was found to be 31.0% by weight. From this measured value, the coefficient n for O (oxygen) was calculated to be 4.25. The value n=4.25 corresponds to 87.6% of n=4.85 which is the most highly oxidized state of the constituting elements of the complex oxide where Mo is hexavalent, V is pentavalent, Te is hexavalent and Nb is pentavalent.
0.5 ml of the catalyst thus obtained, was charged into a reactor. Then, a gas phase catalytic reaction was conducted at a reaction temperature of 440.degree. C. and at a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:10. The results are shown in Table 2.
EXAMPLES 2 AND 3
Complex oxides having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n were prepared in the same manner as in Example 1 except that the temperature for calcination in Example 1 was changed to 500.degree. C. and 600.degree. C.
The results of the powder X-ray diffraction of the complex oxides are shown in Table 1. Further, the results of the gas phase catalytic reactions are shown in Table 2.
COMPARATIVE EXAMPLE 1
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 O.sub.n was prepared in the same manner as in Example 2 except that the niobium component in Example 2 was not used.
The X-ray diffraction pattern of the complex oxide was totally different from that of Example 1. The results of the gas phase catalytic reaction are shown in Table 2.
COMPARATIVE EXAMPLE 2
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n was prepared in the same manner as in Example 1 except that calcination in Example 1 was conducted under an air stream at 350.degree. C. for two hours. The powder X-ray diffraction pattern of the complex oxide thus obtained, is shown in FIG. 2. The pattern is entirely different from the pattern in FIG. 1 representing Example 1.
Further, the results of the gas phase catalytic reaction are shown in Table 2.
COMPARATIVE EXAMPLES 3 AND 4
Using the complex oxide of Comparative Example 2, the gas phase catalytic reaction was conducted under the reaction conditions as identified in Table 2. The results are shown in Table 2.
EXAMPLE 4
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Sb.sub.0.1 O.sub.n was prepared as follows.
In 117 ml of warm water, 4.21 g of ammonium metavanadate was dissolved, and 4.13 g of telluric acid and 15.9 g of ammonium paramolybdate were sequentially added thereto to obtain a uniform aqueous solution. Further, 1.56 g of antimony chloride oxide was dissolved in 17.9 ml of water and mixed thereto. The obtained aqueous solution was evaporated to dryness to obtain a dried product.
This dried product was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 500.degree. C. for two hours. The results of the powder X-ray diffraction of the complex oxide thus obtained are shown in Table 1.
With respect to the complex oxide thus obtained, the gas phase catalytic reaction was conducted, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 5
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Sb.sub.0.1 O.sub.n was prepared in the same manner as in Example 4 except that the calcination in Example 4 was conducted under an air stream at 350.degree. C. for two hours. The X-ray diffraction pattern of the complex oxide thus obtained, was entirely different from that of Example 4. Further, using the complex oxide thus obtained, a gas phase catalytic reaction was conducted, and the results are shown in Table 2.
EXAMPLE 5
A complex oxide was prepared in the same manner as in Example 4 except that 3.38 g of aluminum nitrate nonahydrate was used instead of antimony chloride oxide in Example 4. The empirical formula of the complex oxide thus obtained, was Mo.sub.1 V.sub.0.4 Te.sub.0.2 Al.sub.0.1 O.sub.n. The results of the powder X-ray diffraction of the complex oxide thus obtained are shown in Table 1. Further, using the oxide thus obtained, a gas phase catalytic reaction was conducted, and the results are shown in Table 2.
COMPARATIVE EXAMPLE 6
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Al.sub.0.1 O.sub.n was prepared in the same manner as in Example 5 except that the calcination in Example 5 was conducted under an air stream at 350.degree. C. for two hours. The X-ray diffraction pattern of the complex oxide thus obtained, was entirely different from that of Example 5. Further, using the complex oxide thus obtained, a gas phase catalytic reaction was conducted, and the results are shown in Table 2.
EXAMPLE 6
A complex oxide was prepared in the same manner as in Example 4 except that 0.415 g of palladium nitrate was used instead of antimony chloride oxide in Example 4 and the temperature for calcination was changed to 600.degree. C. The empirical formula of the complex oxide thus obtained, was Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 Pd0.02O.sub.n. The results of the powder X-ray diffraction of the complex oxide thus obtained, are shown in Table 1. Further, using the complex oxide thus obtained, a gas phase catalytic reaction was conducted, and the results are shown in Table 2.
EXAMPLES 7 to 23
Complex oxides having the respective empirical formulas as identified in Table 1, were prepared in the same manner as in Example 1 except that the proportions of the starting material compounds were changed and the temperature for calcination was 600.degree. C. in each case. The results of the powder X-ray diffraction of the respective complex oxides are shown in Table 1. Further, using the respective complex oxides, gas phase catalytic reactions were conducted, and the results are shown in Table 3.
EXAMPLES 24 TO 32
Using the complex oxide prepared in Example 3 (empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n), gas phase catalytic oxidation reactions were conducted under various conditions, and the results are shown in Table 4.
TABLE 1__________________________________________________________________________ Relative intensities of X-ray diffraction peaks at diffractionExample Complex oxides angles of 2.theta. (.+-. 0.30)Nos. (atomic ratios) 22.1.degree. 28.2.degree. 36.2.degree. 45.2.degree. 50.0.degree.__________________________________________________________________________1 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 100 79.5 21.0 10.9 12.32 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 100 92.8 18.7 11.5 13.23 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 100 93.0 24.9 12.9 14.44 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Sb.sub.0.1 O.sub.n 100 122.5 36.1 12.2 23.05 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Al.sub.0.1 O.sub.n 100 97.4 27.6 13.7 20.06 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 Pd.sub.0.02 O.sub.n 100 80.9 21.8 11.1 12.67 Mo.sub.1 V.sub.0.3 Te.sub.0.2 Nb.sub.0.15 O.sub.n 100 63.6 17.4 12.4 11.08 Mo.sub.1 V.sub.0.375 Te.sub.0.2 Nb.sub.0.175 O.sub.n 100 87.6 25.1 15.6 16.99 Mo.sub.1 V.sub.0.35 Te.sub.0.2 Nb.sub.0.15 O.sub.n 100 46.5 12.6 15.0 7.910 Mo.sub.1 V.sub.0.334 Te.sub.0.2 Nb.sub.0.167 O.sub.n 100 63.8 17.6 13.1 10.911 Mo.sub.1 V.sub.0.25 Te.sub.0.2 Nb.sub.0.15 O.sub.n 100 51.7 13.6 12.8 8.812 Mo.sub.1 V.sub.0.32 Te.sub.0.2 Nb.sub.0.13 O.sub.n 100 67.5 20.2 13.9 12.313 Mo.sub.1 V.sub.0.34 Te.sub.0.2 Nb.sub.0.12 O.sub.n 100 78.9 22.2 13.8 15.514 Mo.sub.1 V.sub.0.2 Te.sub.0.2 Nb.sub.0.14 O.sub.n 100 54.7 14.9 13.6 9.315 Mo.sub.1 V.sub.0.56 Te.sub.0.2 Nb.sub.0.14 O.sub.n 100 107.7 27.5 13.7 21.116 Mo.sub.1 V.sub.0.45 Te.sub.0.2 Nb.sub.0.05 O.sub.n 100 113.9 24.7 11.4 16.517 Mo.sub.1 V.sub.0.3 Te.sub.0.2 Nb.sub.0.2 O.sub.n 100 37.0 9.7 10.7 5.718 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.2 O.sub.n 100 69.9 18.2 10.3 11.219 Mo.sub.1 V.sub.0.3 Te.sub.0.2 Nb.sub.0.1 O.sub.n 100 89.9 26.2 14.7 16.820 Mo.sub.1 V.sub.0.48 Te.sub.0.2 Nb.sub.0.12 O.sub.n 100 104.7 26.2 13.3 16.121 Mo.sub.1 V.sub.0.28 Te.sub.0.2 Nb.sub.0.14 O.sub.n 100 51.5 14.8 12.2 8.822 Mo.sub.1 V.sub.0.4 Te.sub.0.1 Nb.sub.0.1 O.sub.n 100 67.5 18.0 18.0 11.523 Mo.sub.1 V.sub.0.4 Te.sub.0.3 Nb.sub.0.1 O.sub.n 100 109.3 29.2 13.2 17.9__________________________________________________________________________
TABLE 2__________________________________________________________________________ Feed gas Selectiv- Calcination composition ity Yield of conditions Reaction Space (mol %) Conversion acrylo- acrylo- Complex oxides Temp. Gas temp. velocity propane/ of propane nitrile nitrile (atomic ratios) (.degree.C.) stream (.degree.C.) (hr.sup.-1) ammonia/air (%) (%) (%)__________________________________________________________________________Example 1 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 620 N.sub.2 420 1,000 1/1.2/15 79.4 63.5 50.4Example 2 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 500 N.sub.2 400 500 1/1.2/10 54.4 39.4 21.4Example 3 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 600 N.sub.2 420 1,000 1/1.2/15 78.3 61.2 48.0Comparative Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 500 N.sub.2 440 1,000 1/1.2/15 43.4 36.7 15.9Example 1Comparative Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 350 air 400 500 1/1.2/10 42.9 34.4 14.8Example 2Comparative Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 350 air 420 500 1/1.2/10 43.2 27.1 11.7Example 3Comparative Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n 350 air 440 1,000 1/1.2/10 48.8 34.2 16.7Example 4Example 4 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Sb.sub.0.1 O.sub.n 500 N.sub.2 420 500 1/1.2/10 47.7 45.5 21.7Comparative Mo.sub.1 V.sub.0.4 Te.sub.0.2 Sb.sub.0.1 O.sub.n 350 air 400 500 1/1.2/10 43.0 36.6 15.7Example 5Enample 5 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Al.sub.0.1 O.sub.n 500 N.sub.2 440 500 1/1.2/10 60.3 39.1 23.5Comparative Mo.sub.1 V.sub.0.4 Te.sub.0.2 Al.sub.0.1 O.sub.n 350 air 420 500 1/1.2/10 52.7 33.3 17.5Example 6Esample 6 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 Pd.sub.0.02 O.sub.n 600 N.sub.2 420 1,000 1/1.2/15 79.4 63.5 50.4__________________________________________________________________________
TABLE 3__________________________________________________________________________ Feed gas Selectiv- composition ity of Yield of Reaction Space (mol %) Conversion acrylo- acrylo-Example Complex oxides temp velocity propane/ of propane nitrile nitrileNos. (atomic ratios) (.degree.C.) (hr.sup.-1) ammonia/air (%) (%) (%)__________________________________________________________________________7 Mo.sub.1 V.sub.0.3 Te.sub.0.2 Nb.sub.0.15 O.sub.n 420 1,000 1/1.2/15 89.1 60.0 53.58 Mo.sub.1 V.sub.0.375 Te.sub.0.2 Nb.sub.0.175 O.sub.n 420 1,000 1/1.2/15 88.4 52.8 46.79 Mo.sub.1 V.sub.0.35 Te.sub.0.2 Nb.sub.0.15 O.sub.n 410 1,000 1/1.2/15 86.0 55.3 47.610 Mo.sub.1 V.sub.0.334 Te.sub.0.2 Nb.sub.0.167 O.sub.n 430 1,000 1/1.2/15 90.4 55.9 50.911 Mo.sub.1 V.sub.0.25 Te.sub.0.2 Nb.sub.0.15 O.sub.n 400 1,000 1/1.2/15 75.3 60.2 45.312 Mo.sub.1 V.sub.0.32 Te.sub.0.2 Nb.sub.0.13 O.sub.n 420 1,000 1/1.2/15 92.7 57.5 53.313 Mo.sub.1 V.sub.0.39 Te.sub.0.2 Nb.sub.0.12 O.sub.n 420 1,000 1/1.2/15 91.0 54.5 49.614 Mo.sub.1 V.sub.0.2 Te.sub.0.2 Nb.sub.0.14 O.sub. n 400 1,000 1/1.2/15 60.5 64.0 38.715 Mo.sub.1 V.sub.0.56 Te.sub.0.2 Nb.sub.0.14 O.sub.n 430 1,000 1/1.2/15 50.6 62.3 31.516 Mo.sub.1 V.sub.0.45 Te.sub.0.2 Nb.sub.0.05 O.sub.n 430 1,000 1/1.2/15 52.4 56.3 29.517 Mo.sub.1 V.sub.0.3 Te.sub.0.2 Nb.sub.0.2 O.sub.n 440 1,000 1/1.2/15 77.2 56.2 43.418 Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.2 O.sub.n 430 1,000 1/1.2/15 79.6 61.7 49.119 Mo.sub.1 V.sub.0.3 Te.sub.0.2 Nb.sub.0.1 O.sub.n 420 1,000 1/1.2/15 83.0 62.1 51.620 Mo.sub.1 V.sub.0.48 Te.sub.0.2 Nb.sub.0.12 O.sub.n 430 1,000 1/1.2/15 75.4 59.3 44.721 Mo.sub.1 V.sub.0.28 Te.sub.0.2 Nb.sub.0.14 O.sub.n 410 1,000 1/1.2/15 82.8 63.3 52.422 Mo.sub.1 V.sub.0.4 Te.sub.0.1 Nb.sub.0.1 O.sub.n 430 500 1/1.2/10 67.7 56.1 38.023 Mo.sub.1 V.sub.0.4 Te.sub.0.3 Nb.sub.0.1 O.sub.n 420 1,000 1/1.2/15 44.6 48.6 21.7__________________________________________________________________________
TABLE 4__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space (mol %) Conversion acrylo- acrylo-Example Temp. velocity propane/ of propane nitrile nitrileNos. (.degree.C.) (hr.sup.-1) ammonia/air (%) (%) (%)__________________________________________________________________________24 420 1,000 1/0.7/15 82.5 53.1 43.825 420 1,000 1/0.9/15 82.8 57.5 47.626 420 1,000 1/1.5/15 81.4 60.9 49.627 420 1,000 1/1.2/10 62.9 63.8 40.128 420 1,000 1/1.2/17 82.6 57.6 47.529 420 500 1/1.2/10 63.0 56.6 35.730 420 800 1/1.2/15 84.9 57.9 49.231 420 1,200 1/1.2/15 77.8 61.7 48.032 410 1,000 1/0.7/15 76.2 59.1 45.0__________________________________________________________________________
EXAMPLE 33
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n was prepared as follows.
In 325 ml of warm water, 15.7 g of ammonium metavanadate was dissolved, and 23.6 g of telluric acid and 78.9 g of ammonium paramolybdate were sequentially added thereto to obtain a uniform aqueous solution. Further, 117.5 g of an aqueous ammonium niobium oxalate solution having a niobium concentration of 0.456 mol/kg was added thereto to obtain a slurry. This slurry was evaporated to dryness to obtain a solid. This solid was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
The powder X-ray diffraction of the complex oxide thus obtained was measured (using Cu--K.alpha.-rays), whereby main diffraction peaks were observed at diffraction angles of 2.theta. (.degree.) of 22.1 (100), 28.2 (90.0), 36.2 (25.7), 45.1 (15.2) and 50.0 (16.3) (the numerical values in the blackets indicate the relative peak intensities based on the peak at 22.1.degree. being 100).
Then, 30 g of the complex oxide was pulverized in a mortar, and 0.3 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was then calcined in a nitrogen stream at 500.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained, was charged into a reactor, and the gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and at a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 5.
EXAMPLE 34
A solid catalyst was prepared in the same manner as in Example 33 except that the amount of the tetravalent antimony oxide (Sb.sub.2 O.sub.4) in Example 33 was changed to 0.15 g, and the reaction was conducted under the same conditions as in Example 33. The results are shown in Table 5.
EXAMPLE 35
A solid catalyst was prepared in the same manner as in Example 34 except that the calcination after the addition of the tetravalent antimony oxide in Example 34 was conducted under a nitrogen stream at 550.degree. C. for two hours, and the reaction was conducted under the same conditions as in Example 33. The results are shown in Table 5.
EXAMPLE 36
30 g of the same complex oxide as in Example 33 was pulverized in an agate mortar, and 3 g of an aqueous ammonium antimony tartarate solution (corresponding to 10% by weight of Sb.sub.2 O.sub.3) was added and mixed thereto. The solid of this mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in an air stream at 300.degree. C. for one hour and further in a nitrogen stream at 500.degree. C. for two hours. Using the solid catalyst thus obtained, the reaction was conducted under the same conditions as in Example 33. The results are shown in Table 5.
EXAMPLE 37
Using a complex oxide comprising Mo, V, Te and Nb prepared in the same manner as in Example 33 except that antimony oxide was not added, the reaction was conducted under the same conditions as in Example 33. The results are shown in Table 5.
EXAMPLE 38
A complex oxide having the same catalyst composition as in Example 33 was prepared under a condition where tetravalent antimony oxide (Sb.sub.2 O.sub.4) was present from the initial stage, as opposed to adding tetravalent antimony oxide (Sb.sub.2 O.sub.4) after preparing a complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n.
Namely, 15.7 g of ammonium metavanadate was dissolved in 325 ml of warm water, and 23.6 g of telluric acid and 78.9 g of ammonium paramolybdate were sequentially added to obtain a uniform aqueous solution. Further, 117.5 g of an aqueous ammonium niobium oxalate solution having a niobium concentration of 0.456 mol/kg was mixed thereto to obtain a slurry. To this slurry, 0.98 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) was further added and mixed. This slurry was evaporated to dryness to obtain a solid. This solid was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
Using the solid catalyst thus obtained, the reaction was conducted under the same conditions as in Example 33. The results are shown in Table 5.
EXAMPLE 39
A complex oxide was prepared in the same manner as in Example 38 except that the calcination in a nitrogen stream in Example 38 was conducted at 500.degree. C. for two hours, and the reaction was conducted under the same conditions as in Example 33. The results are shown in Table 5.
TABLE 5______________________________________ Selectivity Conversion for Yield of of propane acrylonitrile acrylonitrile (%) (%) (%)______________________________________Example 33 91.5 63.7 58.3Example 34 89.3 63.4 56.7Example 35 86.5 65.6 56.7Example 36 88.1 63.8 56.2Example 37 86.7 63.5 55.1Example 38 67.2 49.4 33.2Example 39 45.9 48.3 22.2______________________________________
EXAMPLES 40 TO 68
Using the solid catalyst prepared in Example 33, reactions were conducted under various conditions, and the results are shown in Table 6.
EXAMPLES 69 TO 102
Using the solid catalyst prepared in Example 34, reactions were conducted under various conditions, and the results are shown in Table 7.
EXAMPLES 103 TO 109
Using the solid catalyst prepared in Example 37, reactions were conducted under various conditions, and the results are shown in Table 8.
When the Examples in Table 8 are compared with the Examples in Tables 6 and 7, it is evident that under the same reaction conditions, the selectivity and yield are higher in a case where antimony oxide was added later than in a case where antimony oxide was not added later.
TABLE 6__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space Reaction (mol %) Conversion acrylo- acrylo-Example velocity temp. propane/ of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) ammonia/air (%) (%) (%)__________________________________________________________________________40 1,000 410 1/0.6/15 90.0 53.4 48.141 1,000 410 1/0.75/15 89.9 58.3 52.442 1,000 410 1/0.9/15 89.6 61.9 55.543 1,000 410 1/1.05/15 90.4 63.0 57.044 1,000 410 1/1.35/15 91.6 64.3 58.945 1,000 410 1/1.5/15 90.9 64.9 59.046 1,000 410 1/1.65/15 90.4 65.0 58.847 1,000 410 1/1.8/15 89.4 65.2 58.248 1,200 410 1/0.75/10 75.7 66.8 50.649 1,200 410 1/0.9/10 75.0 68.6 51.550 1,200 410 1/0.75/12 83.7 62.6 52.351 1,200 410 1/0.9/12 83.6 66.9 56.052 1,200 410 1/1.2/12 83.1 68.8 57.253 1,200 410 1/0.75/15 86.3 61.7 53.254 1,200 410 1/0.9/15 87.1 63.8 55.555 1,200 410 1/1.2/15 86.3 66.3 57.256 1,200 410 1/1.5/15 86.2 66.9 57.757 1,500 410 1/0.75/10 73.7 66.5 49.058 1,500 410 1/0.9/10 74.3 68.2 50.759 1,500 410 1/1.2/10 68.9 68.7 47.360 1,500 410 1/0.75/12 79.5 66.1 52.661 1,500 410 1/0.9/12 80.4 69.0 55.462 1,500 410 1/1.2/12 79.5 70.4 55.963 1,500 410 1/0.75/15 81.5 64.9 52.964 1,500 410 1/0.9/15 82.0 66.9 54.865 1,500 410 1/1.2/15 82.1 67.3 55.366 1,500 410 1/1.5/15 81.9 68.9 56.467 1,500 400 1/1.2/15 77.1 68.6 52.968 1,500 420 1/1.2/15 88.3 63.7 56.2__________________________________________________________________________
TABLE 7__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space Reaction (mol %) Conversion acrylo- acrylo-Example velocity temp. propane/ of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) ammonia/air (%) (%) (%)__________________________________________________________________________69 1,000 400 1/0.6/15 89.5 56.9 51.070 1,000 400 1/0.75/15 89.8 60.9 54.771 1,000 400 1/0.9/15 89.8 63.2 56.872 1,000 400 1/1.5/15 88.2 61.9 54.673 1,000 400 1/0.75/15 77.5 64.2 49.874 1,000 400 1/0.75/12 87.3 63.7 55.675 1,000 400 1/0.9/12 87.0 64.9 56.576 1,000 400 1/1.2/12 83.4 63.5 52.977 1,200 400 1/0.75/10 77.8 67.1 52.178 1,200 400 1/0.9/10 76.7 67.7 51.979 1,200 400 1/0.75/12 83.9 66.2 55.580 1,200 400 1/0.9/12 83.4 67.6 56.481 1,200 400 1/1.2/12 82.0 66.7 54.882 1,200 410 1/0.9/12 87.5 63.3 55.483 1,200 400 1/0.75/15 85.4 64.5 55.184 1,200 410 1/0.75/15 90.9 59.6 54.285 1,200 400 1/0.9/15 85.5 66.8 57.286 1,200 410 1/0.9/15 90.3 62.6 56.587 1,200 400 1/1.2/15 86.2 64.5 55.688 1,200 410 1/1.2/15 91.2 63.5 57.989 1,200 400 1/1.5/15 84.8 64.1 54.390 1,200 410 1/1.5/15 91.0 65.5 59.791 1,200 400 1/1.8/15 89.3 65.0 58.192 1,500 400 1/0.6/10 75.3 67.5 50.893 1,500 400 1/0.75/10 75.6 69.0 52.294 1,500 400 1/0.9/10 73.9 69.4 51.395 1,500 400 1/0.75/12 78.9 68.3 53.996 1,500 400 1/0.75/12 78.5 68.9 54.197 1,500 410 1/0.9/12 83.3 67.5 56.298 1,500 400 1/1.2/12 77.3 67.3 52.099 1,500 410 1/0.9/15 86.4 64.8 55.9100 1,500 410 1/1.2/15 87.1 66.6 58.1101 1,500 410 1/1.5/15 86.2 67.1 57.8102 1,500 410 1/1.8/15 85.4 66.8 57.1__________________________________________________________________________
TABLE 8__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space Reaction (mol %) Conversion acrylo- acrylo-Example velocity temp. propane/ of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) ammonia/air (%) (%) (%)__________________________________________________________________________103 1,000 410 1/0.6/15 83.0 56.8 47.1104 1,000 410 1/0.75/15 82.3 61.4 50.5105 1,000 410 1/0.9/15 82.8 64.2 53.1106 1,000 410 1/1.5/15 82.8 66.2 54.8107 1,000 410 1/1.8/15 80.6 63.6 51.3108 1,200 410 1/0.75/10 73.8 65.3 48.2109 1,500 410 1/0.75/10 73.8 65.3 48.2__________________________________________________________________________
EXAMPLES 110 TO 114
A complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n was prepared as follows.
In 117 ml of warm water, 4.21 g of ammonium metavanadate was dissolved, and 4.13 g of telluric acid and 15.9 g of ammonium paramolybdate were sequentially added thereto to obtain a uniform aqueous solution. Further, 21.9 g of an aqueous ammonium niobium oxalate solution having a niobium concentration of 0.41 mol/kg was mixed thereto to obtain a slurry. This slurry was evaporated to dryness to obtain a solid. This solid was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
The powder X-ray diffraction of the complex oxide thus obtained was measured (using Cu--K.alpha.-rays), whereby main diffraction peaks at diffraction angles of 2.theta. (.degree.) of 22.1 (100), 28.2 (79.5), 36.2 (21.0), 45.2 (10.9) and 50.0 (12.3) were observed (the numerical values in the brackets represent relative peak intensities based on the peak at 22.1.degree. being 100).
Then, 10 g of the complex oxide was pulverized in a mortar, and 0.1 of trivalent antimony oxide (Sb.sub.2 O.sub.3) was further added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and reactions were conducted under various conditions. The results are shown in Table 9.
COMPARATIVE EXAMPLES 115 TO 118
Using a complex oxide comprising Mo, V, Te and Nb prepared in the same manner as in Example 110 except that antimony oxide was not incorporated, reactions were conducted under various conditions, and the results are shown in Table 9.
Even when the reaction temperature was raised to be higher by 10.degree. C. than Example 115 to increase the conversion of propane, the yield and selectivity are higher when antimony oxide was added, as is evident from the comparison of Examples having the same feed gas composition.
TABLE 9__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space Reaction (mol %) Conversion acrylo- acrylo-Example velocity temp. propane/ of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) ammonia/air (%) (%) (%)__________________________________________________________________________110 1,000 420 1/1.2/15 89.3 60.1 53.7111 1,000 420 1/0.6/15 90.1 50.7 45.7112 1,000 420 1/0.75/15 90.4 55.7 50.4113 1,000 420 1/0.9/15 90.4 58.2 52.7114 1,000 420 1/1.5/15 87.9 59.8 52.6115 1,000 430 1/0.6/15 88.2 47.0 41.5116 1,000 430 1/0.9/15 88.5 56.0 49.5117 1,000 430 1/1.2/15 88.2 58.5 51.6118 1,000 430 1/1.5/15 86.5 59.0 51.0__________________________________________________________________________
EXAMPLES 119 to 122
A catalyst was prepared in the same manner as in Example 110 except that tetravalent antimony oxide (Sb.sub.2 O.sub.4) was used for the addition of antimony oxide to the complex oxide comprising Mo, V, Te and Nb in Example 110, and reactions were conducted under various conditions. The results are shown in Table 10.
EXAMPLE 123
A complex oxide having the same catalyst composition as in Example 110 was prepared under such a condition that tetravalent antimony oxide (Sb.sub.2 O.sub.4) was present from the initial stage as opposed to adding tetravalent antimony oxide (Sb.sub.2 O.sub.4) after the preparation of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.4 Te.sub.0.2 Nb.sub.0.1 O.sub.n.
Namely, in 117 ml of warm water, 4.21 g of ammonium metavanadate was dissolved, and 4.13 g of telluric acid and 15.9 g of ammonium paramolybdate were sequentially added thereto to obtain a uniform aqueous solution. Further, 21.9 g of an aqueous ammonium niobium oxalate solution having a niobium concentration of 0.41 mol/kg was added thereto to obtain a slurry. Further, to this slurry, 0.2 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) was added and mixed. This slurry was evaporated to dryness to to obtain a solid. This solid was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
Using the catalyst thus obtained, the reaction was conducted under the conditions as identified in Table 10. the results are shown in the same Table.
EXAMPLE 124
A complex oxide was prepared in the same manner as in Example 123 except that the calcination in a nitrogen stream in Example 123 was conducted at 500.degree. C. for two hours, and the reaction was conducted under the conditions as identified in Table 10. The results are also shown in the same Table.
TABLE 10__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space Reaction (mol %) Conversion acrylo- acrylo-Example velocity temp. propane/ of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) ammonia/air (%) (%) (%)__________________________________________________________________________119 1,000 420 1/0.6/15 89.8 51.3 46.1120 1,000 420 1/0.75/15 90.2 57.0 51.5121 1,000 420 1/0.9/15 90.0 59.2 53.3122 1,000 420 1/1.2/15 89.4 59.1 52.8123 1,000 430 1/1.2/15 74.3 59.5 44.2124 1,000 410 1/1.2/15 41.6 39.6 16.5__________________________________________________________________________
EXAMPLE 125
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n prepared as described in Example 33, was pulverized, and 0.3 g of orthoboric acid (H.sub.3 BO.sub.3) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 11.
EXAMPLE 126
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.2 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.6 g of orthoboric acid (H.sub.3 BO.sub.3) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 125. The results are shown in Table 11.
EXAMPLE 127
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.9 g of orthoboric acid (H.sub.3 BO.sub.3) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 125. The results are shown in Table 11.
TABLE 11______________________________________ Selectiv- ity for Yield of Conversion acrylo- acrylo- of propane nitrile nitrile (%) (%) (%)______________________________________Example 125 89.0 63.2 56.2Example 126 91.6 63.3 58.0Example 127 87.9 65.5 57.6______________________________________
EXAMPLE 128
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.2 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.3 g of bismuth oxide (Bi.sub.2 O.sub.3) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 12.
EXAMPLE 129
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.6 g of bismuth oxide (Bi.sub.2 O.sub.3) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase oxidation reaction of propane was conducted under the same reaction conditions as in Example 128. The results are shown in Table 12.
EXAMPLE 130
A solid catalyst was prepared in the same manner as in Example 129 except that the temperature for calcination in a nitrogen stream after the addition of bismuth oxide in Example 129 was changed to 800.degree. C., and a gas phase catalytic oxidation reaction of propane was conducted in the same manner as in Example 129. the results are shown in Table 12.
EXAMPLE 131
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.9 g of bismuth oxide (Bi.sub.2 O.sub.3) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 128. The results are shown in Table 12.
EXAMPLE 132
0.5 ml of the solid catalyst prepared as described in Example 128 was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 400.degree. C. and at a space velocity SV of 1,000 hr.sup.-1, by supplying a feed gas in a molar ratio of propane:ammonia:air=1:0.75:15. The results are shown in Table 12.
EXAMPLES 133 TO 140
Using the solid catalyst prepared by the method as described in Example 129, gas phase catalytic oxidation reactions of propane were conducted under various reaction conditions. The results are shown in Table 12.
TABLE 12__________________________________________________________________________ Feed gas Selectiv- composition ity for Yield of Space Reaction (mol %) Conversion acrylo- acrylo-Example velocity temp. propane/ of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) ammonia/air (%) (%) (%)__________________________________________________________________________128 1,000 410 1/1.2/15 96.4 58.5 56.4129 1,000 410 1/1.2/15 93.5 60.3 56.3130 1,000 410 1/1.2/15 83.2 67.5 56.2131 1,000 410 1/1.2/15 90.0 63.6 57.3132 1,000 400 1/0.75/15 96.5 55.2 53.3133 1,500 410 1/0.75/12 83.9 66.9 56.2134 1,500 420 1/0.75/12 87.8 64.9 57.0135 1,500 410 1/0.9/12 84.0 66.8 56.1136 1,500 420 1/0.9/12 88.2 66.0 58.2137 1,500 410 1/0.75/15 85.8 65.8 56.5138 1,500 420 1/0.75/15 90.4 62.7 58.7139 1,500 410 1/0.9/15 85.1 66.8 56.9140 1,500 420 1/0.9/15 90.4 63.6 57.5__________________________________________________________________________
EXAMPLE 141
30 g of the composite oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.3 g of cerium oxide (CeO.sub.2) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 600.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 420.degree. C. and at a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 13.
EXAMPLE 142
0.5 ml of the solid catalyst prepared as described in Example 141 was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 430.degree. C. and at a space velocity SV of 1,500 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 13.
EXAMPLE 143
A solid catalyst was prepared in the same manner as in Example 141 except that the amount of cerium oxide in Example 141 was changed to 0.6 g. 0.5 ml of the solid catalyst thus prepared was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 430.degree. C. and at a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 13.
EXAMPLE 144
0.5 ml of the solid catalyst prepared as described in Example 143 was charged into a reactor, and a gas phase reaction was conducted at a reaction temperature of 440.degree. C. and at a space velocity SV of 1,500 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 13.
COMPARATIVE EXAMPLES 145 to 147
Using a complex oxide comprising Mo, V, Te and Nb prepared in the same manner as in Examples 141 to 143 except that cerium oxide was not added, a gas phase catalytic oxidation reaction of propane was conducted under the same conditions as in Examples 141 to 143. The results are shown in Table 13.
TABLE 13______________________________________ Selectiv- ity for Yield of Space Reaction Conversion acrylo- acrylo-Example velocity temp. of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) (%) (%) (%)______________________________________141 1,000 420 93.2 58.4 54.7142 1,500 430 87.5 64.9 56.8143 1,000 430 91.8 57.1 52.4144 1,500 440 88.9 61.2 54.4145 1,000 420 94.2 56.7 53.4146 1,500 430 94.2 57.2 53.8147 1,000 430 91.3 53.8 49.2______________________________________
EXAMPLE 148
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.225 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) and 0.6 g of bismuth oxide (Bi.sub.2 O.sub.3) were added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained, was charged into a reactor, and a gas phase reaction was conducted at a reaction temperature of 410.degree. C. and a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 14.
EXAMPLE 149
30 g of the complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 prepared as described in Example 33, was pulverized, and 0.1125 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) and 0.3 g of bismuth oxide (Bi.sub.2 O.sub.3) were added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours.
0.5 ml of the solid catalyst thus obtained, was charged into a reactor, and a gas phase reaction was conducted at a reaction temperature of 400.degree. C. and a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 14.
EXAMPLE 150
0.5 ml of the solid catalyst prepared as described in Example 149 was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and at a space velocity SV of 1,500 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 14.
EXAMPLE 151
To 5 ml of water, 0.277 g of bismuth nitrate pentahydrate (Bi(NO.sub.3).sub.3.5H.sub.2 O) was added, and 0.167 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) was further added. The mixture was evaporated to dryness. The solid thus obtained was calcined in an air stream at 600.degree. C. for two hours.
To the solid thus obtained, 30 g of the composite oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n prepared as described in Example 33, was added and mixed. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours. Here, the atomic ratio of Sb:Bi was 2:1.
0.5 ml of a solid catalyst thus obtained, was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 14.
EXAMPLE 152
0.5 ml of a solid catalyst prepared as described in Example 150, was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and at a space velocity SV of 1,500 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 14.
TABLE 14______________________________________ Selectiv- ity for Yield of Space Reaction Conversion acrylo- acrylo-Example velocity temp of propane nitrile nitrileNos. (hr.sup.-1) (.degree.C.) (%) (%) (%)______________________________________150 1,000 410 90.1 64.0 57.6151 1,000 400 94.5 59.0 55.8152 1,500 410 90.5 63.7 57.7153 1,000 410 94.8 61.1 57.9154 500 410 89.0 64.7 57.6______________________________________
EXAMPLE 155
30 g of the composite oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n prepared as described in Example 33, was pulverized, and 0.225 g of tetravalent antimony oxide (Sb.sub.2 O.sub.4) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a product of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for two hours. 0.5 ml of a solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 420.degree. C. and at a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of isobutane:ammonia:air=1:1.2:15.
As a result, the conversion of isobutane was 61.4%, the selectivity for methacrylonitrile was 33.0, and the yield of methacrylonitrile was 20.3%.
EXAMPLE 156
Using a complex oxide comprising Mo, V, Te and Nb prepared in the same manner as in Example 155 except that antimony oxide was not added, a gas phase catalytic oxidation reaction of isobutane was conducted under the same conditions as in Example 155.
As a result, the conversion of isobutane was 64.1%, the selectivity for methacrylonitrile was 29.7%, and the yield of methacrylonitrile was 18.1%.
EXAMPLE 157
A material having silica incorporated in an amount of 10% by weight, based on the total amount, to a complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n, was prepared as follows.
In 117 ml of warm water, 3.79 g of ammonium metavanadate was dissolved, and 3.72 g of telluric acid and 14.30 g of ammonium paramolybdate were sequentially added thereto to obtain a uniform aqueous solution. Further, 3.59 g of ammonium niobium oxalate dissolved in 17.9 ml of water and 10.24 g of silica sol (silica content: 20% by weight) were added thereto to obtain a slurry. This slurry was evaporated to dryness at 150.degree. C. to obtain a dried product.
This dried product was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at a temperature of 600.degree. C. for 4 hours.
The powder X-ray diffraction of the complex oxide thus obtained, was measured, whereby main diffraction peaks were observed at diffraction angles of 2.theta. (.degree.) of 22.1 (100), 28.2 (41.7), 36.2 (10.0), 45.2 (13.1) and 50.1 (7.1) (the numerical values in the brackets indicate the relative peak intensities based on peak at 22.1.degree. being 100).
0.5 ml of the material thus obtained was charged into a reactor, and a gas phase catalytic oxidation reaction was conducted at a reaction temperature of 420.degree. C. and a space velocity SV of 1,000 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. As a result, the conversion of propane was 88.9%, the selectivity for acrylonitrile was 60.5%, and the yield of acrylonitrile was 53.8%.
EXAMPLE 158
A gas phase catalytic oxidation reaction of isobutane was conducted in the same manner as in Example 157 except that the complex oxide of Example 3 was used.
As a result, the conversion of isobutane was 52.1%, the selectivity for methacrylonitrile was 31.0%, and the yield of methacrylonitrile was 16.2%.
COMPARATIVE EXAMPLE 5
A gas phase catalytic oxidation reaction of isobutane was conducted in the same manner as in Example 157 except that the complex oxide of Comparative Example 2 was used.
As a result, the conversion of isobutane was 11.0%, the selectivity for methacrylonitrile was 42.7%, and the yield of methacrylonitrile was 4.7%.
According to the process of the present invention, it is posssible to produce a desired nitrile at a relatively low temperature at a level of from 400.degree. to 450.degree. C. in good yield without necessity of the presence of a halide or water in the reaction system, by using a novel complex oxide catalyst and an alkane as the starting material.
EXAMPLE 159
30 g of a complex oxide having an empirical formula Mo.sub.1 V.sub.0.3 Te.sub.0.23 Nb.sub.0.12 O.sub.n prepared in the same manner as in Example 33 was pulverized in a mortar, and 0.3 g of manganese oxide (MnO.sub.2) was added and mixed thereto. This mixture was molded into a tablet of 5 mm in diameter and 3 mm in length by a tabletting machine, followed by pulverization and sieving to obtain a powder of from 16 to 28 mesh. The powder was calcined in a nitrogen stream at 550.degree. C. for 2 hours.
0.5 ml of a solid catalyst thus obtained was charged into a reactor, and a gas phase catalytic reaction was conducted at a reaction temperature of 410.degree. C. and at a space velocity SV of 1,300 hr.sup.-1 by supplying a feed gas in a molar ratio of propane:ammonia:air=1:1.2:15. The results are shown in Table 15.
EXAMPLE 160
Using the solid catalyst prepared in Example 159, a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 159 except that the space velocity SV was changed to 19,000 hr.sup.-1. The results are shown in Table 1.
EXAMPLE 161
30 g of a complex oxide prepared in the same manner as in Example 159 was pulverized, and 0.3 g of chromium oxide (Cr.sub.2 O.sub.3) was added and mixed thereto. Then, preparation of a solid catalyst was carried out in the same manner as in Example 159.
Using the solid catalyst thus obtained, a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 159 except that the reaction temperature was changed to 420.degree. C., and the space velocity SV was changed to 11,000 hr.sup.-1. The results are shown in Table 15.
EXAMPLE 163
30 g of a complex oxide prepared in the same manner as in Example 159 was pulverized, and 0.3 g of yttrium oxide (Y.sub.2 O.sub.3) was added and mixed thereto. Then, preparation of a solid catalyst was carried out in the same manner as in Example 159.
Using the solid catalyst thus obtained, a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 159 except that the reaction temperature was changed to 430.degree. C. and the space velocity SV was changed to 2,000 hr.sup.-1. The results are shown in Table 15.
EXAMPLE 164
30 g of a complex oxide prepared in the same manner as in Example 159 was pulverized, and 0.3 g of germanium oxide (GeO.sub.2) was added and mixed thereto. Then, preparation of a solid catalyst was carried out in the same manner as in Example 159.
Using the solid catalyst thus obtained, a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 159. The results are shown in Table 15.
EXAMPLE 165
Using the solid catalyst prepared in Example 164, a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 164 except that the reaction temperature was changed to 420.degree. C. and the space velocity SV was changed to 19,000 hr.sup.-1. The results are shown in Table 15.
EXAMPLE 166
30 g of a complex oxide prepared in the same manner as in Example 159 was pulverized, and 0.3 g of lead oxide (PbO) was added and mixed thereto. Then, preparation of a solid catalyst was carried out in the same manner as in Example 159.
Using the solid catalyst thus obtained, a gas phase catalytic oxidation reaction of propane was conducted under the same reaction conditions as in Example 159 except that the reaction temperature was changed to 420.degree. C. and a space velocity SV was changed to 15,000 hr.sup.-1. The results are shown in Table 15.
EXAMPLE 167
A reaction was conducted under the same conditions as in Example 159 using only the complex oxide comprising Mo, V, Te and Nb without addition of manganese oxide in Example 159. The results are shown in Table 15.
From the comparison between Examples 159 to 166 and Example 167 in Table 15, it is evident that the yield of acrylonitrile is higher in the cases where catalysts having specific compounds incorporated, were used.
TABLE 15__________________________________________________________________________ Selectivity Conversion for Yield of Added Tempera- of Propane acrylonitrile acrylo- oxide SV (hr.sup.-1) ture (.degree.C.) (%) (%) nitrile (%)__________________________________________________________________________Example 159 MnO.sub.2 1300 410 93.4 59.6 55.7Example 160 MnO.sub.2 1900 420 88.6 63.4 56.2Example 161 Cr.sub.2 O.sub.3 1900 410 91.9 61.3 56.3Example 162 Ga.sub.2 O.sub.3 1100 420 90.2 61.1 55.1Example 163 Y.sub.2 O.sub.3 2000 430 91.6 61.2 56.1Example 164 GeO.sub.2 1300 410 94.0 59.7 56.1Example 165 GeO.sub.2 1900 420 89.5 63.8 57.1Example 166 Pbo 1500 420 89.7 62.6 56.1Example 167 Nil 1300 410 89.7 60.1 53.9__________________________________________________________________________

Number	Date	Country
3-0199573	Aug 1991	JPX
4-18962	Feb 1992	JPX
5-18923	Feb 1993	JPX

Number	Name	Date
4415752	Decker et al.	Nov 1983
4568790	McCain	Feb 1986
4966990	Otake et al.	Oct 1990
5206201	Kishimoto et al.	Apr 1993

Catalyst for the production of nitriles

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (3)

Parent Case Info

US Referenced Citations (4)

Divisions (1)

Continuation in Parts (1)