NOBLE METAL-MOLECULAR SIEVE CATALYSTS

摘要

Exhaust gas catalysts are disclosed. One exhaust gas catalyst comprises a noble metal and a molecular sieve, and has an infrared spectrum having a characteristic absorption peak from 750 cm−1 to 1050 cm−1 in addition to the absorption peaks for the molecular sieve itself. The exhaust gas catalyst also comprises a noble metal and a molecular sieve, having greater than 5 percent of the noble metal amount located inside pores of the molecular sieve. The exhaust gas catalyst also comprises a first and second molecular sieve catalyst. The first molecular sieve catalyst comprises a first noble metal and a first molecular sieve, and the second molecular sieve catalyst comprises a second noble metal and a second molecular sieve. The first and second molecular sieves are different. The invention also includes exhaust systems comprising the exhaust gas catalysts, and a method for treating exhaust gas utilizing the exhaust gas catalysts.

主权项

1. An exhaust gas catalyst effective to adsorb NOx and hydrocarbons (HC) at or below a low temperature and to convert and release the adsorbed NOx and HC at temperatures above the low temperature, said exhaust gas catalyst comprising a first molecular sieve catalyst and a second molecular sieve catalyst, wherein the first molecular sieve catalyst comprises a first noble metal and a first molecular sieve, and the second molecular sieve catalyst comprises a second noble metal and a second molecular sieve, wherein the first molecular sieve is different than the second molecular sieve.