Promotional Effects of FeOx on the Commercial SCR Catalyst for the Synergistic Removal of NO and Dioxins from Municipal Solid Waste Incineration Flue Gas

In view of the atmospheric pollutants in flue gas raised by municipal solid waste (MSW) incineration, simultaneous abatement of nitric oxide and dioxins is the keystone to alleviate the existing environmental issues. By using the commercial selective catalytic reduction (SCR) catalyst, nitric oxide and dioxins can be directly removed in separate temperature windows, while the catalytic performances still remain unsatisfactory. Herein, a collection of commercial V2O5–MoO3/TiO2 (VMT) catalysts modified with transition metal oxides were prepared in this study, and their synergistic removal activities for NO and dioxins were systematically investigated. Catalyst performance tests indicated that the loading of FeOx demonstrated considerable promotional effects. To further elucidate the enhancing mechanism of FeOx doping on the physical and chemical properties of the catalyst, a series of characterizations were conducted. The results indicated that FeOx increased the specific surface area and pore volume of the catalyst, which was more conducive to the dispersion of vanadium species. The modification with FeOx also enriched surface acid centers, as well as the V5+ species on the catalyst surface, so that the adsorption and destruction efficiencies of both nitric oxide and dioxins were further increased. Furthermore, the abundant chemisorbed oxygen species and the redox capacity of the catalyst were intensified, owing to the newly formed Fe3+–V4+/Fe2+–V5+ catalytic redox cycle.