Catalytic combustion is a chemical process which uses a catalyst to speed desired oxidation reactions of a fuel and so reduce the formation of undesired products, especially pollutant nitrogen oxide gases (NOx) far below what can be achieved without catalysts. The process was discovered in the 1970s at Engelhard Corp. Catalytic combustion is a chemical process which uses a catalyst to speed desired oxidation reactions of a fuel and so reduce the formation of undesired products, especially pollutant nitrogen oxide gases (NOx) far below what can be achieved without catalysts. The process was discovered in the 1970s at Engelhard Corp.