EXHAUST GAS PURIFICATION CATALYST AND EXHAUST GAS PURIFICATION METHOD USING SAID CATALYST

摘要

As a way to suppress deterioration of catalytic performance in an exhaust gas purification catalyst even after being exposed to an exhaust gas containing a phosphorus compound, an exhaust gas purification catalyst is provided. The catalyst purifies an exhaust gas containing a phosphorus compound, and the catalyst includes a catalyst layer containing rhodium (Rh), palladium (Pd), and either a ceria-zirconia-lanthana complex oxide or a ceria-zirconia-lanthana-yttria complex oxide as catalyst active components. Further, an average value of distances between Rh particles and the nearest Pd particles of the Rh and the Pd is within 4000 nm, a weight ratio of the Pd to the Rh is from 0.2 to 4.9, and a content rate of yttria in the ceria-zirconia-lanthana-yttria complex oxide is 19% by weight or less.

主权项

1. An exhaust gas purification catalyst purifying an exhaust gas containing a phosphorus compound, the catalyst comprising:
a catalyst layer A containing rhodium (Rh), palladium (Pd), and either a ceria-zirconia-lanthana complex oxide or a ceria-zirconia-lanthana-yttria complex oxide as catalyst active components, wherein an average value of distances between Rh particles and the nearest Pd particles of the Rh and the Pd is within 4000 nm, a weight ratio of the Pd to the Rh is from 0.2 to 4.9, and a content rate of yttria in the ceria-zirconia-lanthana-yttria complex oxide is 19% by weight or less.