Abstract: The invention relates to a process for the manufacture of a catalyst for the reduction of nitrogen oxides in exhaust gases. The catalyst contains a metal oxide. The catalyst is preferably used for catalytic reduction with ammonia. The process comprises screening a natural goethite iron ore to the required grain size and then treating the ore with sulfuric acid. Subsequently, the goethite iron ore is heated to a temperature which approximately equals the temperature at which it will be used in the catalytic reaction.

Abstract: In a process for the manufacture of catalyst moldings a natural raw material containing Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3 or another such catalyst component such as TiO.sub.2, NbO.sub.2, WO.sub.3, V.sub.2 O.sub.5 or MoO.sub.3 is screened to a grain size equal to or less than approximately 0.25 mm. This screened base mixture is thoroughly blended, and then preferably a concentrated sulphuric acid is added. This mixture of material is then pressed into a molding in a hydraulic press with a pressure of approximately 500 bar to produce the molding.

Abstract: A catalyst for use with ammonia for the selective reduction of nitrogen oxides in waste gases. The catalyst comprises a mixture of substances which has high activity and selectivity with regard to nitrogen oxide conversion and high sorption capabilities with regard to ammonia, but low oxidation capabilities with regard to sulfur dioxide, ammonia, or similar substances. The invention also provides a process for the manufacture and use of such catalysts.