Highly efficient removal of toluene over Cu-V oxides modified γ-Al2O3 in the presence of SO2.

Developing efficient catalysts with good resistance to complex flue gas is essential for VOCs removal in coal-fired flue gas. In this study, by exploring the effect of transition metal oxide additive, metal loading and bimetallic synergy on toluene oxidation in coal-fired flue gas, 10Cu-3V/γ-Al2O3 is identified as the optimal catalyst. It achieves 90% of CO2 generation at 350 ℃, which is decreased by ca. 46 ℃ compared with 13Cu/γ-Al2O3. And it also exhibits good resistance to H2O and good stability. ICP-OES, N2 adsorption-desorption isotherms, XRD, TEM, XPS, EPR and H2-TPR analyses were applied to characterize the catalyst composition and physicochemical properties. Doping V into 13Cu/γ-Al2O3 not only leads to better dispersity of CuO and homogeneous elements distribution that benefits to produce more active centers, but also constitutes the redox cycle of V5+ + Cu+ ↔ V4+ + Cu2+ which induces more surface chemical oxygen (Osur). Moreover, since SO2 is the main inhibiting factor in toluene oxidation, the SO2 poisoning mechanism was illustrated by XPS, TG and in situ DRIFT analyses in depth.