Selective catalytic reduction of nitrogen oxides

摘要

The present invention relates to a catalyst for selective reduction of nitrogen oxides and comprises also a process for selective reduction of nitrogen oxides in oxygen-containing effluent gases, either separately or in combination with a non-catalytic selective reduction process. The catalyst constitutes a beta -zeolite having a silica to alumina ratio of at least 10 and an average kinetic pore diameter of at least 5 Angstroms. Copper promoter is present in amounts of 0.1-10 % by weight of the zeolite and palladium or rhodium promoter is present in amounts of 0.01-1.0 % by weight.