CATALYST FOR PURIFYING EXHAUST GAS OF ENGINE

摘要

PURPOSE:To suppress the poisoning of Pd by S and to obtain a catalyst contg. Pd as a catalytic component and excellent in the low-temp. activation of hydrocarbon. CONSTITUTION:A 1st catalyst 1 with a Pd carried coating layer on the surface of the carrier is placed and a 2nd catalyst 2 obtd. by carrying a transition metal such as Ni or Cu on at least one kind of oxide having a large specific surface area such as CeO2 or Al2O3 or carrying zeolite with a carried metal having high oxidizing power such as V or Fe on a honeycomb carrier is disposed on the upper stream side of the 1st catalyst 1. Since SOx is adsorbed on the transition metal-contg. catalyst or the oxidation of SOx is accelerated by the catalyst with the carried V or Fe, the poisoning of the Pd by S is suppressed.