Catalyst for purifying exhaust gases from internal combustion engines and gas turbines operated at above the stoichiometric ratio

A catalyst for purifying exhaust gases comprising a full solid, one-piece exhaust-gas purifying reduction catalyst in honeycomb form for selective reduction of nitrogen oxides contained in said exhaust gases by ammonia gas or by an ammonia producing compound said honeycomb having a trailing-edge portion which is coated with an oxidation catalyst capable of oxidizing components in said exhaust gases, and said coated portion amounts to 20-50% of the total volume of said catalyst.