Catalyst for exhaust gas purification

Abstract

An exhaust gas purifying catalyst includes a metal-containing silicate and a noble metal active species carried by the metal-containing silicate. The metal-containing silicate has a solid acid characteristic wherein the amount of acid within a region where an acidity function Ho is equal to or smaller than -3.0 ranges from 0.04 to 0.55 mmol/gr. The noble metal active species burns an hydrocarbon component of exhaust gases to decompose an NOx component also contained in the exhaust gases. The catalyst may include a binder for carrying the noble metal active species on the metal-containing silicate. The binder has a solid acid characteristic wherein the amount of acid within a region where the acidity function Ho is equal to or smaller than -3.0 ranges from 0.04 to 0.55 mmol/gr.

Dependencies are inferred from the claim text.