Toyota Jidosha Kabushiki Kaisha

Norio Taguchi

Mikio Murachi

Takeru Yoshida

Shinji Tsuji

Kazuyuki Toki

Juji Suzuki

This catalyst support aims to improve heat resistant and durability by highly dispersing an NO.sub.x storage component. This catalyst support is produced by mixing a solution of a chemical compound including at least one element of alkali metals, alkaline-earth metals, and rare-earth elements with a solution of oxide sol of at least one metal of group IIIb, group IVa, and group IVb in the periodic table to prepare a mixed sol solution, forming the mixed sol solution into gel, and drying and calcining the gel. The obtained catalyst support is amorphous and attains a high specific surface area even when calcined at elevated temperatures, so that the catalyst support is superior in heat resistance.

High heat-resistant catalyst with a porous ceria support

A process for producing an exhaust-gas-purifying catalyst includes the steps of immersing a porous support into a solution including a noble metal catalyst ingredient, thereby preparing a support with a noble metal catalyst ingredient loaded thereon, and thermally treating the noble-metal-catalyst-ingredient-loaded support at a temperature of 800.degree. C. or more in non-oxidizing atmosphere. In the thermally-treating step, the noble metal catalyst ingredient is prevented from being oxidized to its oxide, and accordingly it is inhibited from migrating in vapor phase. Further, in the thermally-treating step, pores of the porous support are contracted so that they surround the noble metal catalyst ingredient closely therein. All in all, the noble metal catalyst ingredient is prevented from sintering. Thus, the resulting exhaust-gas-purifying catalyst is of superb heat-resistance, and it can be applied to elevated temperatures of 800.degree. C. or more in fuel-lean atmosphere.

Process for producing exhaust-gas-purifying catalyst

A shaped body is molded from fine particles such as powder, whiskers and short fibers, by preparing a slurry consisting of the fine particles and a supercritical fluid containing a small amount of binder dissolved therein, and supplying the slurry into a mold cavity through an inlet port, so that the fine particles suspended in the supercritical fluid are stacked in the cavity to form a layer as the supercritical fluid is exhausted out of the mold cavity through an outlet port.

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Susono, Japan

Norio Taguchi