ZEOLITE HAVING COPPER AND ALKALI EARTH METAL SUPPORTED THEREON.

摘要

A chabazite-type zeolite having copper and an alkali earth metal supported thereon. It is preferred that the alkali earth metal is at least one metal selected from the group consisting of calcium, magnesium and barium. It is also preferred that the SiO2/Al2O3 ratio is 10-50 by mole and that the (copper atoms)/(aluminum atoms) ratio is 0.15-0.25. The chabazite-type zeolite exhibits a higher nitrogen oxide purification rate than those of conventional chabazite-type zeolite catalysts on which only copper is supported, after being subjected to a water/heat-durable treatment.