| 摘要 |
PROBLEM TO BE SOLVED: To provide an alloy catalyst for cleaning of an exhaust gas, especially to provide an alloy catalyst having excellent purification characteristics of nitrogen oxides in a high temp. region with optimum heat resistance and catalytic activity and with a low coating rate when first catalyst metal particles are coated with a second metal phase. SOLUTION: This alloy catalyst for cleaning of an exhaust gas has a structure deposited on a metal oxide and consists of first catalyst metal particles coated with a second metal phase of one or more metals different from the first catalyst metal particles with <45 % coating rate. The coating rate θof the second metal phase to the first catalyst metal particles and the weight ratio M of the second metal phase/first catalyst metal particles satisfy the relation of θ/M>=5,000. The first catalyst metal particles and second metal phase consist of one or more elements of Pt. Pd, Au, Rh, Ag and Ir. |
