Abstract: Three-dimensional knitted catalyst gauzes made from noble metals have recently come into use for ammonia oxidation and other gaseous reactions. Particularly high yields accompanied by a stable course of the reaction and an extended service life of the catalyst gauze are achieved if the catalyst gauzes are knitted in two or more layers and the layers are connected together by pile threads. Important features are the largest possible number of pile threads per unit area and the alignment thereof as parallel as possible to the direction of flow of the reaction gases.

Abstract: There is provided a catalyst for the oxidation of ammonia for the production of nitrogen oxides consisting of a gauze packet of platinum-rhodium alloy and non-noble metal alloys in which at least a part of the individual gauzes of the gauze packets contain both wires of platinum-rhodium alloy and also of oxidation resistant, heat resistant non-noble metal alloys.