Patent ID: 8512662

Claim:
A method for decomposing nitrogen oxides using a mixed metal oxide catalyst, the method comprising the steps of: i) providing a catalyst layer comprising a mixed metal oxide catalyst prepared from a hydrotalcite-type or brucite-type compound precursor, a catalyst wherein a precious metal is impregnated or intercalated into the mixed metal oxide catalyst, or a catalyst wherein a co-catalyst is added and a non-precious metal is impregnated or intercalated into the mixed metal oxide catalyst; ii) passing a waste gas containing oxygen and nitrogen oxides and having an oxygen concentration of 0.01% or more, through the catalyst layer, to selectively adsorb the nitrogen oxides on the catalyst layer; iii) passing a reducing agent through the catalyst layer having the nitrogen oxides adsorbed thereon; and iv) decomposing and desorbing the adsorbed nitrogen oxides by the reducing agent.