Selective reduction catalyst, and exhaust gas purification device and exhaust gas purification method using same

Abstract

The selective reduction-type catalyst effectively purifies nitrogen oxides contained in exhaust gas from a lean-burn engine such as a boiler, a gas turbine or a lean-burn engine, a diesel engine, even under high SV, as well as having small pressure loss, by supplying by spraying urea water or ammonia water, as a reducing component, to the selective reduction-type catalyst; and an exhaust gas purification apparatus along with an exhaust gas purification method using the same. The selective reduction-type catalyst for selectively reducing a nitrogen oxide by adding urea or ammonia as a reducing agent of the nitrogen oxide to exhaust gas discharged from a lean-burn engine, characterized by coating a catalyst layer including zeolite containing at least an iron element, and a composite oxide of silica, tungsten oxide, ceria and zirconia, as denitration components, at the surface of a monolithic structure-type substrate.