Breaking the Activity–Selectivity Trade-Off for Simultaneous Catalytic Elimination of Nitric Oxide and Chlorobenzene via FeVO<sub>4</sub>–Fe<sub>2</sub>O<sub>3</sub> Interfacial Charge Transfer
Rongqiang Yin, Jianjun Chen, Jinxing Mi, Haiyan Liu, Tao Yan, Liang Shan, Junyu Lang, Junhua Li
Abstract
Removing chlorinated organics (chlorobenzene as a model) by a deNOx unit over a bifunctional catalyst has become the frontier of environmental catalysis. However, it is fundamentally challenging to achieve efficient selective catalytic reduction of NOx and chlorobenzene catalytic oxidation due to the trade-off between activity and selectivity. Herein, we demonstrated to break such trade-off through interfacial charge modulation on a bifunctional catalyst that is fabricated by integrating FeVO4 and Fe2O3 semiconductor materials. The optimized FeVO4–Fe2O3 catalyst exhibited stable bifunctional removal efficiencies (>95%) for NOx and chlorobenzene with high HCl selectivity (>85%), surpassing the state-of-the-art V2O5–WO3/TiO2 catalyst. It is identified from the experimental and theoretical results that the charge transferred from Fe in Fe2O3 to V and Fe cations in FeVO4 through the interfacial oxygen atoms. The formed gap states decreased the work function and promoted the redox ability of FeVO4, enhancing the bifunctional catalytic activity. Correspondingly, the Fermi level of Fe2O3 shifted to a lower position, which increased the HCl selectivity and inhibited polychlorinated byproducts. The interfacial charge transfer broke the activity–selectivity trade-off and ensured remarkable bifunctional performance, providing an efficient strategy to design advanced catalysts for multipollutant control.