CATALYST FOR EXHAUST GAS PURIFICATION

摘要

NOx purification efficiency after long periods of use can be improved. Disclosed is a catalyst for exhaust gas purification (1) that includes particles (31) comprising oxygen storing materials, particles (32) comprising one or more alkaline earth metal elements and/or a compound thereof that are positioned between the particles (31), and particles (33) comprising one or more noble metal elements that are positioned between the particles (31). The characteristic X-ray intensity spectrum of one of the alkaline earth metal elements and the characteristic X-ray intensity spectrum of one of the noble metal elements, which are obtained through linear analysis using energy dispersive X-ray spectroscopy over a length of 500 nm, have a correlation coefficient s (AE, PM) of at least 0.70.