Catalyst for exhaust gas purification

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The purpose of the present invention is to provide an exhaust gas purification catalyst having improved exhaust gas purification performance (in particular, NOx purification performance) at low to medium temperatures. To achieve said purpose, the present invention provides an exhaust gas purification catalyst (10A) provided with a substrate (20), and a catalyst layer (30 or 40) provided on the substrate (20), wherein : the catalyst layer (30 or 40) includes a rhodium element, a phosphorus element, and a rare earth element other than a cerium element; the ratio of the mass of the phosphorus element included in the catalyst layer (30 or 40) to the mass of the rhodium element included in the catalyst layer (30 or 40) is 1 to 10; and the ratio of the mass, in terms of oxide, of the rare earth element which is other than the cerium element and included in the catalyst layer (30 or 40), to the mass of the rhodium element included in the catalyst layer (30 or 40) is 1 to 5.