CATALYST FOR PURIFYING EXHAUST GAS

摘要

PURPOSE:To obtain a catalyst having superior heat resistance and catalytic activity by carrying a specified catalytic element on modified zeolite having a specified rate of Al removal and a specified molar ratio of SiO2 to Al2O3. CONSTITUTION:Unmodified zeolite is subjected to Al removal treatment at 10-25% rate of Al removal to regulate the molar ratio of SiO2 to Al2O3 to 30-80 and to obtain heat resistant modified zeolite. A catalytic element made of at least one of at least one kind of metal selected from among Cu, Co, Fe and Pt and oxide of the metal is carried on the modified zeolite by 1-10wt.% to produce the objective catalyst having superior heat resistance and catalytic activity.