Metal - metal oxide - doped oxide catalysts with a high denox - selectivity for lean - nox - exhaust aftertreatment systems

摘要

A lean - nox - catalyst and to a method for the preparation of this is disclosed. The lean - nox - catalyst has a ceramic substrate, an oxide carrier material, preferably gamma - of aluminum oxide, which is deposited on the substrate, and a metal reaction agent or a doping, which, in the oxide carrier material has been initiated. The metal reaction agent or - dopants are selected from the group consisting of the following substances: indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium, cerium, vanadium, oxides thereof, and combinations thereof. The gamma - aluminum oxide preferably has a pore volume of about 0,5 to about 2,0 cm cm · 3 · / g; a surface area between about 80 to 350 m · 2 · / g; an average diameter of the pore size of between 3 and 30 nm and a level of impurities of less than or equal to 0,2% by weight of. In a preferred embodiment, the gamma - aluminum oxide by means of a sol gel - - prepared by means of the method, wherein the metal doping of the gamma - aluminum oxide preferably using an impregnation art is carried out with initial moisture.