Method of preparing doped oxide catalysts for lean NOx exhaust

Abstract

The lean NOx catalyst includes a substrate, an oxide support material, preferably γ-alumina deposited on the substrate and a metal or metal oxide promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium cerium, and vanadium, and oxides thereof, and any combinations thereof. The γ-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between 80 and 350 m2/g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to about 0.2 weight percent. In a preferred embodiment the γ-alumina is prepared by a sol-gel method, with the metal doping of the γ-alumina preferably accomplished using an incipient wetness impregnation technique.

Dependencies are inferred from the claim text.