Catalyst for purifying exhaust gas, process for production thereof, exhaust gas purifying filter, and exhaust gas purifying apparatus

摘要

A catalyst for exhaust gas purification characterized by high catalytic activity, heat resistance, and toxin resistance includes a metal oxide and at least one alkali metal sulfate or at least one alkaline earth metal sulfate. The process for producing the catalyst includes mixing the metal oxide with an aqueous solution of the sulfate, evaporating the mixture to dryness, and heat-treating the resultant mixed powder. An exhaust gas purifying apparatus includes an exhaust gas purifying filter having a high exhaust gas purification rate and an excellent durability. The filter includes a ceramic filter with a heat-resistant coating layer thereon for support of the catalyst.