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, Jr and Pt.
摘要:
Provided is novel catalyst for treating NOx in an exhaust gas, wherein the catalyst comprises a metal promoted high SAR zeolite having an AFX framework.
摘要:
Provided is a catalyst composition comprising a small pore molecular sieve, about 0.5-5 weight percent of a transition metal (TM) selected from copper and/or iron, based on the total weight of the zeolite, and about 0.5-5 weight percent nickel, based on the total weight of the molecular sieve, wherein the transition metal and nickel are present in a TM:Ni ratio of about 10:1 to about 1:2. Also provided is a synthesis method for preparing a small pore molecular sieve having both Cu and Ni incorporated in situ. Also provided is a method for using such a catalyst for selectively reducing NOx in an exhaust gas.
摘要:
A catalytic material for treating an exhaust gas produced by a natural gas engine, which catalytic material comprises a molecular sieve and a platinum group metal (PGM) supported on the molecular sieve, wherein the molecular sieve has a framework comprising silicon, oxygen and optionally germanium, and has a content of heteroatom T-atoms is ≦about 0.20 mol %.
摘要:
A catalyst article including a substrate with an inlet side and an outlet side, a first zone and a second zone, where the first zone includes a passive NOx adsorber (PNA), and an ammonia slip catalyst (ASC) comprising a platinum group metal on a support and a first SCR catalyst; where the second zone includes a catalyst selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); and where the first zone is located upstream of the second zone. The first zone may include a bottom layer with a blend of: (1) the platinum group metal on a support and (2) the first SCR catalyst; and a top layer with a second SCR catalyst, the top layer located over the bottom layer.
摘要:
Provided is a method for reducing N2O emissions in an exhaust gas comprising contacting an exhaust gas containing NH3 and an inlet NO concentration with an SCR catalyst composition containing small pore zeolite having an SAR of about 3 to about 15 and having about 1-5 wt. % of an exchanged transition metal.
摘要:
Provided is a system for treating a flowing exhaust gas comprising a lean NOx trap, a catalyzed soot filter, an ammonia or an ammonia precursor metering system for metering ammonia or an ammonia precursor into the flowing exhaust gas; and an SCR catalyst, wherein the SCR catalyst is disposed downstream of the lean NOx trap and comprises copper and/or iron supported on a small pore molecular sieve.