Simultaneous catalytic oxidation of Hg0 and AsH3 over Fe–Ce co-doped TiO2 catalyst under low temperature and reducing atmosphere

Abstract

The Fe–Ce bimetal oxide-doped titanium dioxide composite was synthesized by the sol–gel method and the performance of the catalyst was investigated for the removal of Hg⁰ and AsH₃ from yellow phosphorus flue gas under different conditions. Brunauer–Emmett–Teller (BET) analysis, high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the crystal structure and morphology of the structure, and the mechanisms for removing Hg⁰ and AsH₃ from flue gas by catalytic oxidation were deduced. The results showed that the optimal calcination temperature of the Fe₅Ce₅Ti catalyst was 500 °C, and the optimal pH of the sol was 6. Under these conditions, the penetration adsorption capacity of the Fe₅Ce₅Ti catalyst for the removal of AsH₃ and Hg⁰ was 385.5 mg g⁻¹ and 2.178 mg g⁻¹, respectively. According to characterization analysis, Fe and Ce are the main active components in the removal of Hg⁰ and AsH₃, and the mixed oxides of Fe and Ce have a synergistic effect on the surface of the mixed oxide-doped catalyst, which can improve the dispersion of the active component on the surface of the catalyst, and then improve the removal efficiency of Hg⁰ and AsH₃.