EXHAUST GAS PURIFICATION CATALYST

摘要

PROBLEM TO BE SOLVED: To provide an exhaust gas purification catalyst having high NOpurification ability over a wide temperature range.SOLUTION: A silico-aluminophosphate exhaust gas purification catalyst having a chabazite structure with an ion exchange site on Si replaced with copper satisfies the following conditions: 0.07≤Si/(Si+Al+P)≤0.12 (where Si/(Si+Al+P) represents a molar ratio), with a copper ion exchange quantity of 2 to 4 wt.%.