Abstract: A process for manufacturing a carbon catalyst for use in NO.sub.x reduction with ammonia catalyzed by active carbons and active cokes is described. The new carbon catalyst exhibits improved catalytic activity and hence a higher yield in NO. In the manufacturing process, a mixture of ground, oxidized hard coal and binders is moulded, carbonized at temperatures between 700.degree. and 900.degree. C., and then activated with steam at a temperature of 800.degree. to 850.degree. C. for 45 to 100 minutes, until a degree of activation of 5 to 15% is obtained.

Abstract: Process for producing an active catalyst by ammonia treatment of active carbons at high temperatures, in which an active carbon/active coke is impregnated with an aqueous solution of ammonium sulphate, which can be reacted with sulphuric acid, is dried at 120.degree. C. and is then heated in an inert gas stream to temperatures above 350.degree. C. Application of the active carbon catalyst as a reducing and/or oxidizing catalyst, for example for NO.sub.x elimination from exhaust gases using ammonia.