abstract |
An exhaust gas purification catalyst, characterized by having a catalyst layer containing palladium, rhodium, and alumina, which supports a sulfate of an alkaline-earth metal selected from barium sulfate and strontium sulfate, and the correlation coefficients ρ Pd,AE and ρ Rh,AE calculated from the characteristic X-ray intensity measured using an electron beam micro-analyzer for the palladium, rhodium, and alkaline-earth metal being +0.75 to +1.00 and 0.00 to +0.25, respectively, using 350 points as measurement points obtained by equally dividing the catalyst layer into 351 parts in the thickness direction on a virtual straight line that runs through the catalyst layer in the thickness direction. |