Enhancement effect of RuO2 doping on the reduction process of NOx by NH3 via V2O5-WO3/TiO2 particle catalyst under low-temperature: Structure-activity relationship and reaction mechanism.

[Display omitted] • RuO x doping stimulates the high NH 3 -SCR activity of V 2 O 5 -WO 3 /TiO 2 catalyst at low-temperature. • Doping of RuO x promotes the formation of more reactive monodentate nitrates on the surface of V 2 O 5 -WO 3 /TiO 2. • The unique redox cycle and acid cycle matching mechanism consisting of monodentate nitrates and B acid sites on the RuO 2 -V 2 O 5 -WO 3 /TiO 2 surface is formed through L-H mechanism. • RuO x doping accelerates the transfer of oxygen ions on the surface of V 2 O 5 -WO 3 /TiO 2. As a mainstream moderate-high temperature (250–420 °C) particulate denitrification catalyst, V 2 O 5 -WO 3 /TiO 2 (VWT) is not applicable to low-temperature (60–150 °C) iron ore sintering flue gas after semi dry/wet desulfurization. In order to improve the NH 3 -deNO x performance of the VWT particle catalyst at low temperatures, a series of powder VWT denitrification catalysts doped with different content of RuO 2 (R-VWT) prepared by the wet co-impregnation method were researched, and found that the particulate catalyst service temperature (about 100 % NO conversion) is lowered from 225 °C (VWT) to below 175 °C by doping 0.5 % RuO 2. In addition, a series of characterizations indicate that the doped RuO 2 enhances the redox performance of R-VWT and promotes the generation of more surface active intermediate monodentate nitrate, and accelerates the low-temperature surface SCR transient reaction rate. [ABSTRACT FROM AUTHOR]