| abstract |
Provided is a technology that is advantageous in increasing NO x purification performance after long-term use. A provided exhaust gas purification catalyst (1) contains: particles (31) comprising an oxygen-storage material; particles (32) that are disposed between the oxygen-storage particles (31) and that comprise at least one acidic oxide; and particles (33) that are disposed between the oxygen-storage particles (31) and that comprise at least one noble metal. The characteristic X-ray intensity spectrum of one of the non-oxygen elements constituting the acidic oxide(s) and the characteristic X-ray intensity spectrum of one of the noble metal elements, as obtained by energy-dispersive X-ray spectrometry analyzed over a length of 500 nm, have a coefficient of correlation of at least 0.70. |