partial oxidation

catalytic reduction scr

steam reforming

selective catalytic reduction

dry reforming

catalytic oxidation

reforming methane

catalytic reduction

nox reduction

Fuel

• Denitrification performance and stability of modified catalyst are compared. • Structure-activity relationship of zeolite catalysts is reviewed. • Reaction theory and deactivation mechanism are discussed. Air pollution and climate issues are becoming serious, and particularly NO x cause acid rain, ozone hole and disease of respiratory system for humans, which mainly come from automobile and industrial exhaust emissions. Selective catalyst reduction (SCR) with NH 3 as reducing agent is widely employed to eliminate NO x , and the selection of catalyst has a decisive effect in the final conversion. The modification methods of catalysts, such as addition of second metal, replacement of support, optimization of structure, pretreatment and post-treatment are systematically reviewed. For zeolite catalysts, the reaction mechanism and SO 2 poisoning theory are analyzed. In addition, effects of catalyst parameters on denitrification efficiency are summarized, including Si/Al ratio, Cu or Fe loading, specific surface area, coordination structure and calcination temperature. Effects of spatial structure of spinel and perovskite catalysts on catalytic effect are analyzed, and the performance of catalysts with different components is compared. Finally, the current problems of catalyst research are summarized and the development of NH 3 -SCR technology are prospected.

Mechanism, performance and modification methods for NH3-SCR catalysts: A review