Exhaust gas purifying catalyst, and method for producing the same
AssigneeToyota Jidosha Kabushiki Kaisha
InventorShinichi Takeshima
Life of this patent
Estimating the term…
Abstract
An exhaust gas purifying catalyst which is made excellent in heat resistance and in S-resistance by keeping the catalytic activity of Pt particles in a satisfactory state. The exhaust gas purifying catalyst is made such that a coating layer containing a compound oxide of cerium and an oxide of a metal for stabilizing the oxide of said cerium and an oxide containing no cerium is formed on a substrate, and such that platinum particles are carried on the catalyst. Said compound oxide has a pore volume of 0.1 cc/g or more, and said platinum particles are selectively adsorbed at the electrode accepting points on said compound oxide.
Claims16
1-10. (canceled)
An exhaust gas purifying catalyst, in which a coating layer containing a compound oxide of cerium and an oxide of a metal for stabilizing the oxide of said cerium and an oxide containing no cerium is formed on a substrate and on which platinum particles are carried, wherein:
- said compound oxide has a pore volume of 0.1 cc/g or more;
- and
- said platinum particles are selectively adsorbed at the electrode accepting points on said compound oxide.
An exhaust gas purifying catalyst, in which a coating layer containing a compound oxide of cerium and an oxide of a metal for stabilizing the oxide of said cerium and an oxide containing no cerium is formed on a substrate and on which platinum particles are carried, wherein:
- the cerium content of said compound oxide is 30 mols % or less with reference to the total mole number of the metal atoms contained;
- and
- said platinum particles are selectively adsorbed at the electrode accepting points on said compound oxide.
An exhaust gas purifying catalyst, in which a coating layer containing a compound oxide of cerium and an oxide of a metal for stabilizing the oxide of said cerium and an oxide containing no cerium is formed on a substrate and on which platinum particles are carried, wherein:
- the platinum particles are carried at the electrode accepting points in said compound oxide by impregnating said coating layer formed on said substrate with an aqueous solution of organic platinum and by sintering said coating layer.
A method for producing an exhaust gas purifying catalyst, in which a coasting layer containing a compound oxide of cerium and an oxide of a metal for stabilizing the oxide of said cerium and an oxide containing no cerium is formed on a substrate and on which platinum particles are carried, wherein:
- the cerium content of said compound oxide is 30 mols% or less with reference to the total mole number of the metal atoms contained;
- and
- said coating layer is formed by mixing first powder, in which said platinum particles are selectively adsorbed at the electrode accepting points on said compound oxide, and second powder, on which rhodium is carried, into a slurry, by applying the slurry onto the substrate, and then by drying and sintering the slurry.
Dependencies are inferred from the claim text.