The oxynitride catalysts produced by SHS synthesis in the form of powder, granules and cylindrical blocks with the honeycomb structure were used for purification of gaseous mixtures (carbon monoxide, hydrocarbons, and nitrogen oxide) modelling exhaust car gases. Carbon monoxide and propane were oxidized partially at 170 C and completely at 300 C. Methane, the most stable hydrocarbon, was oxidized at 200-550 C. The block honeycomb-structure SHS catalysts are of particular interest. At high flow rates, the conversion degree for carbon monoxide and propane may attain 100%. The temperature of complete oxidation can be lowered upon immobilization of 3d transition metals (Co, Ni, Cr, and Fe). In the case of Ni and Co-immobilized catalysts, carbon monoxide was oxidized at 400-450 C while propane was oxidized at 125-175 C. The efficiency of the SHS ceramic catalysts in the processes of incineration was found to be virtually
identical to that of widespread precious metal catalysts. Therefore, the SHS ceramic catalysts, free of precious metals, may be a competing products to the conventional catalysts for neutralization of engine exhaust and other waste gases.