Contemporary problems in the selective catalytic reduction of nitrogen oxides (NOx)

The results from investigation of the processes involved in the catalytic reduction of nitrogen oxides are reviewed: 1) with carbon monoxide and other combustible gases (H2, CnHm) at a developed block honeycomb palladium-containing catalysts; 2) with ammonia (the SCR process) at vanadium-containing and complex oxide (Cu-Cr, Fe-Cr/γ-Al2O3) catalysts; 3) with light C1-C4 hydrocarbons at cation-exchange zeolites (pentasils, natural and synthetic mordenites). Mechanisms and kinetic models are proposed, and the regions of a positive and negative effect from oxygen and sulfur dioxide on the processes involved in the reduction of nitrogen oxides are established. © 2001 Plenum Publishing Corporation.