Low-temperature selective catalytic reduction of NOx with NH3 over zeolite catalysts: A review

The selective catalytic reduction (SCR) of NOx by NH3 is one of the most mature technologies for NOx treatment. Catalysts are the main factors affecting denitrification efficiency. Zeolites as low-temperature NH3-SCR catalysts have been extensively studied in the past few years. In this work, the mechanism of zeolites for NH3-SCR reaction was reviewed and the denitrification performances of zeolite catalysts prepared by different methods were compared. The effects of sulfur and water poisoning on zeolite catalysts in NH3-SCR reaction were also analyzed. Several ways to address the problems in low-temperature NH3-SCR reaction were discussed. Hopefully, this review could provide a fundamental understanding of SCR reaction on zeolite catalysts and pave the way toward similar studies to realize its commercial applications.