TRANSITION METAL/ZEOLITE SCR CATALYSTS

摘要

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir and Pt.

主权项

1. An exhaust system for treatment of an exhaust gas stream comprising NOx and particulate matter, the exhaust system comprising:
an SCR catalyst substrate containing a catalyst comprising a copper-containing, metal-substituted silicoaluminophosphate having a CHA framework structure; and an ammonia injector or an ammonia precursor injector positioned upstream of the SCR catalyst substrate; wherein the catalyst is effective to promote the reaction of ammonia with nitrogen oxides to form nitrogen and H2O selectively.