Three-way catalysts of improved efficiency
AssigneeEngelhard Corporation
InventorsChung-Zong Wan, Joseph C. Dettling
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Abstract
A three-way catalyst of improved efficiency suitable for simultaneously oxidizing both gaseous hydrocarbons and carbon monoxide, while reducing nitrogen oxides is disclosed. The three-way catalyst includes alumina, a platinum group metal and a rare earth metal oxide having deposited thereon in intimate contact therewith a p-type metal oxide.
Claims17
An improved catalyst active at least for oxidation of hydrocarbons and carbon monoxide in a gas stream, said catalyst being of the type having, dispersed on a refractory support, platinum, particles of ceria and high surface area alumina, wherein the improvement comprises:
- a p-type metal oxide being dispersed on said particles of ceria.
The catalyst active at least for reduction of oxides of nitrogen in a gas stream, said catalyst being of the type having ceria particles and platinum dispersed on a refractory oxide support, wherein the improvement comprises:
- a p-type metal oxide being dispersed on said ceria particles.
Dependencies are inferred from the claim text.