Seven Modern Trends in the DeNO_x Catalyst Development¹

Abstract—As a result of anthropogenic activities, millions of tons of nitrogen oxides (NO_x = NO, NO₂) are emitted into the atmosphere every year, which poses a serious threat to human health. The catalytic neutralization of vehicle exhaust gases and industrial waste gases is the most effective solution to the problem of man-made NO_x emissions. To date, there are a number of catalytic technologies for the removal of nitrogen oxides; however, their use is limited because of their low efficiency at temperatures of 100–300°C. This review is devoted to current trends in the development of highly active catalysts for the removal of nitrogen oxides from vehicle exhaust gases and waste gases of the chemical industry at temperatures below 300°C. The main attention is paid to new catalytic systems based on mixed oxides, hydrotalcites, perovskites, small-pore zeolites, metal–organic frameworks (MOF), and natural minerals and clays, as well as to hybrid catalysts.