Exhaust gas purification catalyst composition and exhaust gas purification catalyst
Provided is a new catalyst that can have heightened purification performance for NOx under lean conditions. Proposed is an exhaust gas purification catalyst composition provided with: a carrier (A) comprising zirconium phosphate; a catalyst active component (a) supported on the carrier (A); a carrier (B) comprising an inorganic oxide porous body; and a catalyst active component (b) supported on the carrier (B).
1. An exhaust gas purification catalyst composition comprising:
a carrier A comprising a zirconium phosphate;
a catalytically active component (a) supported on the carrier A;
a carrier B comprising an inorganic oxide porous material; and
a catalytically active component (b) supported on the carrier B,
wherein the carrier B is one or more inorganic oxide porous materials selected from a group consisting of silica, silica-alumina, ceria-zirconia, lanthanum, alumina, alumino-silicate, alumina-zirconia, alumina-chromia, alumina-ceria titania, and titania,
the catalytically active component (a) comprises Rh,
50% or more of the catalytically active component (a) is supported on the carrier A, and
50% or more of the catalytically active component (b) is supported on the carrier B.
2. The exhaust gas purification catalyst composition according to claim 1 , wherein the carrier B contains an oxide porous material having a Hammett acidity function H 0max of −10<H 0max <15.
3. The exhaust gas purification catalyst composition according to claim 1 , wherein the catalytically active component (b) supported on the carrier B is Pt.
4. The exhaust gas purification catalyst composition according to claim 1 , wherein the catalytically active component (a) supported on the carrier A consists of Rh.
5. An exhaust gas purification catalyst having a structure in which the exhaust gas purification catalyst composition according to claim 1 is supported on a substrate.
6. An exhaust gas purification catalyst having a structure in which the exhaust gas purification catalyst composition according to claim 1 is formed into a pellet shape.
7. The exhaust gas purification catalyst composition according to claim 1 , wherein the carrier B is one or more inorganic oxide porous materials selected from a group consisting of ceria-zirconia, lanthanum, alumina-zirconia, alumina-chromia, and alumina-ceria titania.