Claims
- 1. A process for producing methacrylic acid through vapor phase catalytic oxidation, or vapor phase catalytic oxidation and catalytic oxidative dehydrogenation, or catalytic oxidative dehydrogenation of at least one compound selected from the group consisting of methacrolein, isobutylaldehyde and isobutyric acid with molecular oxygen or a molecular oxygen containing gas, the process being characterized in that it uses a catalyst characterized in that it is a complex oxide composition comprising(A) a complex oxide containing as essential components molybdenum and phosphorus, which is known per se as catalyst for said vapor phase catalytic oxidation and/or vapor phase oxidative dehydrogenation reaction expressed by the following general formula (1): PaMobAcBdCeDfEgOx (1) wherein P is phosphorus; Mo is molybdenum; A is at least one element selected from the group consisting of arsenic, antimony, germanium, bismuth and selenium; B is at least one element selected from the group consisting of copper, silver, iron, cobalt, nickel, lead, manganese, chromium, tin, zinc, palladium, rhodium and tellurium; C is at least one element selected from the group consisting of tungsten, vanadium and niobium; D is at least one element selected from the group consisting of alkali metals and alkaline earth metals; E is at least one element selected from the group consisting of titanium, silicon and aluminum; and O is oxygen; a,b,c,d,e,f g and x denote the atomic ratios of P, Mo, A, B, C, D, E and O respectively; and where b is 12, a is 0.5-4, c is 0.01-3, d is 0.01-5, e is 0.01-5, f is 0.01-6 and g is 0.01-10; and x is determined by the degree of oxidation of each of the elements and(B) a complex oxide containing cerium and zirconium as the essential components.
- 2. The process of claim 1 wherein component (B) of the catalyst is a complex oxide expressed by the following general formula (2):Ce1ZrmFnOy (2) wherein Ce is a cerium; Zr is zirconium; F is at least one element selected from the group consisting of lanthanide series elements except cerium, yttrium, cobalt, nickel, copper, indium, tin, chromium and germanium; and O is oxygen; l, m, n and y denote the atomic ratios of Ce, Zr, F and O respectively, l and m being optional numbers not including 0, n being a number to satisfy the relationship 0≦n/(1+m)<0.1, and y being a number determined by the degree of oxidation of each of the elements.
- 3. The process of claim 1 characterized in that it uses a catalyst characterized by having a composition expressed by the following general formula (3):PaMobCecZrdAeBfCgDhEiGjOx (3) wherein P is phosphorus; Mo is molybdenum; Ce is cerium; Zr is zirconium; A is at least one element selected from the group consisting of arsenic, antimony, germanium, bismuth and selenium; B is at least one element selected from the group consisting of copper, silver, iron, cobalt, nickel, lead, manganese, chromium, tin, zinc palladium, rhodium and tellurium; C is at least one element selected from the group consisting of tungsten, vandium and niobium; D is at least one element selected from the group consisting of alkali metals and alkaline earth metals; E is at least one element selected from the group consisting of titanium, silicon and aluminum; G is at least one element selected from the group consisting of lanthanide series elements except cerium, yttrium and indium; and O is oxygen; a,b,c,d,e,f,g,h,i,j and x denote the atomic ratios of P, Mo, Ce, Zr, A,B,C,D,E,G and O, respectively; and where b is 12, a is 0.5-4, c is 0.01-12, d is 0.01-16, e is 0.01-3, f is 0.01-5, g is 0.01-5, h is 0.01-6, i is 0.01-10 and j is 0.001-2, and x is numerical value determined by degree of oxidation of each the elementsand the cerium and zirconium therein form a complex oxide.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11/119171 |
Apr 1999 |
JP |
|
Parent Case Info
This application is a divisional of prior application Ser. No. 09/557,295 filed Apr. 25, 2000.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4564703 |
Yamamoto et al. |
Jan 1986 |
A |
5206431 |
Hashiba et al. |
Apr 1993 |
A |
Foreign Referenced Citations (1)
Number |
Date |
Country |
09-299803 |
Nov 1997 |
JP |
Non-Patent Literature Citations (1)
Entry |
English Translation of JP 09-299803, by Takako et al. |