Method for the production of an automotive exhaust gas catalyst

Claim 1

The method of claim 1 wherein said nickel compound is a solution of a soluble nickel salt.

Claim 8

A method for preparing a catalyst suitable for use in a catalytic system for oxidation of air pollutants in automotive exhaust gases, said method comprising, in combination, the steps of mixing and kneading a nickel compound selected from the group consisting of a water-soluble nickel salt, nickel hydroxide and nickel oxide and a chromium compound selected from the group consisting of a water-soluble chromium salt, chromic acid, chromium hydroxide and chromium oxide, the atomic ratio of nickel to chromium being 1 : 1 - 12, and the amounts of said nickel compound and chromium compound being such that the total weight of nickel oxide and chromium oxide contained in the final catalyst is 5 - 30%, and, as a binder, a member selected from the group consisting of an alumina sol and a soluble aluminum hydroxide, said binder being used in an amount of 2 - 20%, calculated as alumina, based on the weight of the final catalyst, and, as a carrier, activated alumina having a particle size distribution in the range of 2 - 300 microns and an average particle diameter of not greater than 110 microns, and a water-soluble palladium salt in an amount of 0.01 - 0.1%, calculated as palladium, based on the weight of the final catalyst; molding the resulting mixture with a catalyst molder with a desired shape; drying the molded material at a temperature not exceeding 150*C.; and thereafter calcining the dried material for 3 - 15 hours at a temperature not exceeding 800*C to prepare the final catalyst.

Claim 16

A method for preparing a catalyst of an average pore diameter of 6,000-15,000 A, which is suitable for use in a catalytic system for oxidation of air pollutants in automotive exhaust gases, said method comprising, in combination, the steps of mixing and kneading a nickel compound selected from the group consisting of a water-soluble nickel salt, nickel hydroxide and nickel oxide and a chromium compound selected from the group consisting of a water-soluble chromium salt, chromic acid, chromium hydroxide and chromium oxide, the atomic ratio of nickel to chromium being 1 : 1-12, and the amounts of said nickel compound and chromium compound being such that the total weight of nickel oxide and chromium oxide contained in the final catalyst is 5 - 30%, and, as a binder, a member selected from the group consisting of an alumina sol and a soluble aluminum hydroxide, said binder being used in an amount of 2-20%, calculated as alumina, based on the weight of the final catalyst, and, as a carrier, activated alumina having a particle size distribution in the range of 2-300 microns and an average particle diameter of not greater than 110 microns; molding the resulting mixture with a catalyst molder into a desired shape; drying the molded material at a temperature not exceeding 150*C,; impregnating the dried molded material with a solution of a water-soluble palladium salt in an amount of 0.01 - 0.1%, calculated as palladium, based on the weight of the final catalyst; drying the impregnated material at a temperature not exceeding 150*C.; and thereafter calcining the dried material at a temperature not exceeding 800*C. for 3-15 hours to prepare the final catalyst.

Claim 17

A method for preparing a catalyst of an average pore diameter of 6,000-15,000 A, which is suitable for use in a catalytic system for oxidation of air pollutants in automotive exhaust gases, said method comprising, in combination, the steps of mixing and kneading a nickel compound selected from the group consisting of a water-soluble nickel salt, nickel hydroxide and nickel oxide and a chromium compound selected from the group consisting of a water-soluble chromium salt, chromic acid, chromium hydroxide and chromium oxide, the atomic ratio of nickel to chromium being 1 : 1-12, and the amounts of said nickel compound and chromium being such that the total weight of nickel oxide and chromium oxide contained in the final catalyst is 5-30%, and, as a binder, a member selected from the group consisting of an alumina sol and a soluble aluminum hydroxide, said binder being used in an amount of 2-20%, calculated as alumina, based on the weight of the final catalyst, and, as a carrier, activated alumina having a particle size distribution in the range of 2-300 microns and an average particle diameter of not greater than 110 microns, and a water-soluble palladium salt in an amount of 0.01 - 0.1%, calculated as palladium, based on the weight of the final catalyst; molding the resulting mixture with a catalyst molder into a desired shape; drying the molded material at a temperature not exceeding 150*C.; and thereafter calcining the desired material for 3-15 hours at a temperature not exceeding 800*C. to prepare the final catalyst.

Claim 20

A metHod for preparing a catalyst suitable for use in catalytic system for oxidation of air pollutants in automotive exhaust gases, said method comprising, in combination, the steps of mixing and kneading a nickel compound selected from the group consisting of a water-soluble nickel salt, nickel hydroxide and nickel oxide and a chromium compound selected from the group consisting of a water-soluble chromium salt, chromic acid, chromium hydroxide and chromium oxide, the atomic ratio of nickel to chromium being 1 : 1-12, and the amounts of said nickel compound and chromium compound being such that the total weight of nickel oxide and chromium oxide contained in the final catalyst is 5 - 30%, and, as a binder, a member selected from the group consisting of an aluminum sol and a soluble aluminum hydroxide, said binder being used in an amount of 2 - 20%, calculated as alumina, based on the weight of the final catalyst and, as a carrier, activated alumina having a particle size distribution in the range of 2 - 300 microns and an average particle diameter of not greater than 110 microns; molding the resulting mixture with a catalyst molder into a desired shape; drying the molded material at a temperature not exceeding 150*C.; calcining the dried material at a temperature not exceeding 800*C.; impregnating the calcined molded material with a solution of a water-soluble palladium salt in an amount of 0.01 - 0.1%, calculated as palladium, based on the weight of the final catalyst; drying the impregnated material at a temperature not exceeding 150*C.; and thereafter calcining the dried material at a temperature not exceeding 800*C. for 3 - 15 hours to prepare the final catalyst.

Claim 21

A method for preparing a catalyst of an average pore diameter of 6,000-15,000 A, which is suitable for use in a catalytic system for oxidation of air pollutants in automotive exhaust gases, said method comprising, in combination, the steps of mixing and kneading a water-soluble nickel compound selected from the group consisting of a nickel salt, nickel hydroxide and nickel oxide and a chromium compound selected from the group consisting of a water-soluble salt, chromium acid, chromium hydroxide and chromium oxide, the atomic ratio of nickel to chromium being 1 : 1-12, and the amounts of said nickel compound and chromium compound being such that the total weight of nickel oxide and chromium oxide contained in the final catalyst is 5 -30%, and, as a binder, a member selected from the group consisting of an alumina sol and a soluble aluminum hydroxide, said binder being used in an amount of 2-20%, calculated as alumina, based on the weight of the final catalyst, and, as a carrier, activated alumina being a particle size distribution in the range of 2-300 microns and an average particle diameter of not greater than 110 microns; molding the resulting mixture with a catalyst molder into a desired shape; drying the molded material at a temperature not exceeding 150*C.; calcining the dried material at a temperature not exceeding 800*C.; impregnating the calcined molded material with a solution of a water-soluble palladium salt in an amount of 0.01 - 0.1%, calculated as palladium based on the weight of the final catalyst, drying the impregnated material at a temperature not exceeding 150*C.; and thereafter calcining the dried material at a temperature not exceeding 800*C. for 3-15 hours to prepare the final catalyst.