Patent ID: 7891171
Filing Date: 2011-02-22
Classification: B01D,B01J,Y02A

Abstract:
1. Method for reducing nitrogen oxides including NO and NO 2 in an exhaust stream also comprising oxygen, carbon monoxide and hydrocarbons at a temperature above about 150° C., the method comprising: oxidizing NO in the exhaust stream to NO adding diesel fuel hydrocarbons and their oxygenates to the exhaust stream for the reduction of nitrogen oxides; and contacting the exhaust stream with a hybrid reduction catalyst comprising an alkali metal or an alkaline earth metal, a zeolite, a transition metal, and a metal oxide to reduce the nitrogen oxides to N wherein the hybrid reduction catalyst is prepared from one of the alkali metal and the alkali earth metal, and the zeolite, the transition metal, and the metal oxide through aqueous ion exchange and wet impregnation followed by mixing to form a homogeneous physical mixture, compressing the homogenous physical mixture to form a wafer, and annealing the wafer to form the hybrid catalyst comprising alkali metal or alkali earth metal-zeolite-transition metal/metal oxide.