The effect of Ce on a high-efficiency CeO2/WO3–TiO2 catalyst for the selective catalytic reduction of NOx with NH3

Abstract

In this study, W_0.1TiO_x and Ce_aW_0.1TiO_x (a = 0.1, 0.2, 0.5, 1.0) catalysts were prepared by a novel stepwise precipitation approach. The Ce_aW_0.1TiO_x catalysts showed much better activities and N₂ selectivity than W_0.1TiO_x. Particularly, the Ce_0.2W_0.1TiO_x (CeO₂/WO₃–TiO₂) catalyst showed excellent catalytic performance in a broad temperature range from 200 to 450 °C, under a high GHSV condition of 400 000 h⁻¹. Characterizations revealed that the novel preparation approach can achieve highly dispersed Ce species on the surface of the catalyst, and the Ce species could induce enhanced charge imbalance, superior redox functions, and outstanding adsorption and activation properties for NO_x and NH₃, which is the main reason for the highly efficient NO_x abatement capability of the CeO₂/WO₃–TiO₂ catalyst.