Claims
- 1. A catalyst containing by weight
- (a) about 20 to 98% of a matrix comprising alumina, silica, silica-alumina, alumina boron oxide, magnesia, silica-magnesia, zirconia, titanium oxide, or clay,
- (b) about 2 to 80% of a zeolite having:
- a molar ratio SiO.sub.2 /Al.sub.2 O.sub.3 between about 12 and 40;
- a sodium content less than 0.15% by weight determined on the zeolite calcined at 1100.degree. C.;
- a parameter ao of the elementary mesh comprised between 24.38.times.10.sup.-10 m and 24.26.times.10.sup.-10 m;
- a sodium ion take-up capacity ONa expressed in grams of sodium per 100 grams of zeolite modified, neutralized and calcined higher than about 0.85%;
- a specific surface higher than about 550 m.sup.2 (g);
- a water vapor adsorption capacity at 25.degree. C. (at a P/Po ratio equal to 0.10) higher than 6%;
- (c) 0.01-5% b.w. of at least one noble Group VIII metal or metal compound, or 0.01-15% by weight of at least one group VIII non-noble metal or metal compound, said catalyst being produced by a process consisting essentially of mixing said matrix with said zeolite and introducing in one or several steps into the matrix, into the zeolite or into a mixture thereof, one or more metals or compounds of metals of group VIII or a mixture of metals of group VIII and group VI, and wherein the preparation of the zeolite consists essentially of
- lowering the sodium level of a NaY-zeolite to a value below 2.5% by weight by at least one exchange with a solution of an ionizable ammonium salt, so as to obtain an NH.sub.4 NaY zeolite;
- calcining in at least one step the NH.sub.4 NaY zeolite (hydrothermic treatment) between about 770.degree. and 780.degree. C., at a partial water vapor pressure between about 0.1 and 5 bar for at least 1 hour to obtain a stabilized zeolite, and treating the stabilized zeolite in at least one step by at least one solution of an organic or inorganic acid,
- whereby the resultant zeolite has a pore distribution comprising between 1 and 20% of the pore volume contained in pores of diameter situated between 20.times.10.sup.-10 and 80.times.10.sup.-10 m, the remainder of the pore volume being essentially contained in pores of diameter less than 20.times.10.sup.-10 m.
- 2. A catalyst according to claim 1 containing by weight (a) 50 to 95% of a matrix of a silica-alumina, a silica-magnesia or a clay, and (b) 5 to 50% of the zeolite.
- 3. A catalyst according to claim 2 wherein the matrix contains in addition at least one other solid wherein the solid is an alumina, a silicas, a zirconia, an alumina boron oxide, a magnesia, or a titanium oxide.
- 4. A catalyst according to claim 2 wherein the zeolite contains at least one rare earth metal.
- 5. A catalyst according to claim 2 further containing (c) at least one platinum, rhenium, manganese, chromium, cobalt, nickel, or iron metal.
- 6. A catalyst according to claim 1, wherein the organic or inorganic acid is a hydrochloric or nitric acid solution having a normality of about 0.5-3.
- 7. A catalyst according to claim 1, wherein the normality of the acid solution is about 0.5-3N.
- 8. A catalyst according to claim 1, wherein the sodium ratio is lowered to a value below 0.7% by weight and wherein the temperature of the second hydrothermic treatment is about 770.degree. C.
- 9. A catalyst according to claim 1, wherein the organic or inorganic acid is a hydrochloric or nitric acid solution having a normality of about 0.1-11.
- 10. A catalyst according to claim 1, wherein the sodium ratio is lowered to a value below 1.0% by weight and wherein the temperature of the second hydrothermic treatment is about 770.degree. C.
Priority Claims (1)
Number |
Date |
Country |
Kind |
84 03350 |
Mar 1984 |
FRX |
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Parent Case Info
This application is a continuation, of application Ser. No. 717,775 filed Mar. 29, 1985 (abandoned).
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4120825 |
Ward |
Oct 1978 |
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Foreign Referenced Citations (1)
Number |
Date |
Country |
895873 |
May 1983 |
FRX |
Continuations (1)
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Number |
Date |
Country |
Parent |
717775 |
Mar 1985 |
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