Highly efficient WO-FeO catalysts synthesized using a novel solvent-free method for NH-SCR.

WO-FeO catalysts with various WO contents were synthesized through a facile solvent-free method, satisfying the selective catalytic reduction of NO (NH-SCR). Strikingly, the optimum 30 %WO-FeO catalyst with the largest surface area exhibited the most outstanding catalytic activity, achieving the nearly 100 % NO removal efficiency in a wide temperature window between 225-500 °C, which was better than that of Fe-W series catalysts reported in other studies. In addition, Raman and XPS results proved that the introduction of WO altered the electronic environment of FeO, inducing the formation of FeO (Fe) and surface adsorbed oxygen. In situ DRIFTS demonstrated that the interaction between WO and FeO not only promoted the adsorption capacity of NH on the catalyst, but also contributed to the formation of adsorbed NO species. NO reduction reaction on WO-FeO catalyst proceeded via the Eley-Rideal and Langmuir-Hinshelwood mechanism synchronously. All of these factors, jointly, accounted for the superior catalytic activity and N selectivity of WO-FeO catalysts.