Effects of WO(3) and SiO(2) doping on CeO(2)–TiO(2) catalysts for selective catalytic reduction of NO with ammonia

A series of CeO(2)–WO(3)/SiO(2)–TiO(2) (CeW(x)TiSi(y)) catalysts with different loading amounts of WO(3) were synthesized by wet co-impregnation of ammonium metatungstate and cerium nitrate on a SiO(2)–TiO(2) support, and were employed for the selective catalytic reduction (SCR) of NO by NH(3). The catalytic activity of the CeO(2)/SiO(2)–TiO(2) (CeSiTi) catalyst was enhanced by the addition of WO(3), and the W-containing catalysts showed higher hydrothermal stability especially between 550 and 600 °C. The introduction of WO(3) to the CeSiTi catalyst could produce more chemisorbed oxygen species, reducible subsurface oxygen species, acid sites and ad-NO(x) species. Moreover, the modification of CeO(2)–WO(3)/TiO(2) (CeWTi) by SiO(2) could enhance the specific surface area, especially the aged specific surface area, thus improving the hydrothermal stability of the catalyst.