Selective catalytic reduction of nitrogen oxides by ammonia over the dual-zone FeBeta∥MnCe/FeBeta catalyst

Abstract

The properties of the FeBeta zeolite catalyst, MnCe/FeBeta composite catalyst, and FeBeta∥MnCe/FeBeta dual-zone catalytic system were studied in the selective catalytic reduction of nitrogen oxides with ammonia. The combination of the low-temperature (MnCe/FeBeta) and high-temperature (FeBeta) catalysts makes it possible to significantly improve the efficiency of NOx removal in a wide temperature range (200–500 °C) in the presence of the FeBeta∥MnCe/FeBeta system. It was found that this system also demonstrates high activity in the catalytic oxidation of residual ammonia retaining high selectivity in molecular nitrogen formation even under ammonia excess conditions (NH3: NO > 1).