Abstract: A catalyst for the selective reduction of nitrous oxide with ammonia contains, in addition to titanium oxide as component (A), at least one oxide of W, Si, B, Al, P, Zr, Ba, Y, La, Ce and at least one oxide of Y, Nb, Mo, Fe, Cu as component (B), whereby the atomic ratio between the elements of components (A) and (B) amounts to 1:0.001 up to 1. The catalyst can be obtained by kneading reactive titanium oxide with a high specific surface of predominantly anatase with the substances of component (B) or their preliminary stages, adding processing agents, winding up with a homogeneous kneaded mass, extruding the latter, drying the extrudate and calcining in air at 300.degree.-800.degree. C.

Abstract: A solid catalyst for the oxidation of sulfur dioxide in gas currents containing oxygen, which catalyst includes vanadium oxide and alkali metal oxides, alkali metal sulfates or mixtures thereof, as an active substance, silicon, aluminum, or mixtures thereof, in oxide form, for surface area enlargement, and titanium dioxide in anatase form, rutile form, or mixtures thereof, as a carrier material and a ceramic binder. The metals in these finely sintered components which impart discrete functions are present in certain atomic ratios. The fine sintering takes place according to a production method especially by means of differentiated conditions of drying, calcining and sintering. One use for the invention is the desulfurization of waste gases from combustion processes and industrial plants.

Abstract: A catalyst for the selective reduction of nitrous oxide with ammonia contains, in addition to titanium oxide as component (A), at least one oxide of W, Si, B, Al, P, Zr, Ba, Y, La, Ce and at least one oxide of V, Nb, Mo, Fe, Cu as component (B), whereby the atomic ratio between the elements of components (A) and (B) amounts to 1:0.001 up to 1. The catalyst can be obtained by kneading reactive titanium oxide with a high specific surface of predominantly anatase with the substances of component (B) or their preliminary stages, adding processing agents, winding up with a homogeneous kneaded mass, extruding the latter, drying the extrudate and calcining in air at 300.degree.-800.degree. C.

Abstract: A one-piece catalyst for purifying exhaust gases, particularly from internal combustion engines and gas turbines operated above the stoichiometric ratio. The one-piece honeycomb ceramic or metal carrier has a reduction catalyst on its leading-edge portion and an oxidation catalyst on its trailing-edge portion.

Abstract: A catalyst for the selective reduction with ammonia of nitrogen oxides from an intimate mixture of at least 3 metals in the form of their oxides, namely, titanium, tungsten and at least one of the metals vanadium, iron, niobium, molybdenum, with an atomic ratio of Ti to the other metals of 1:0.001 to 1, wherein there is used as oxide of the titanium a product obtained by flame hydrolysis, which product is impregnated with solutions of the salts of the other metals and is dried and calcined at a high temperature.