Fabrication of wide temperature FexCe1-xVO4 modified TiO2-graphene catalyst with excellent NH3-SCR performance and strong SO2/H2O tolerance
2022
Li, Zhifang | Zhang, Qian | Yang, Jian | Li, Yueyu | Cui, Jinxing | Ma, Yuanyuan | Yang, Changlong
Selective catalytic reduction of NO with NH₃ (NH₃-SCR) is one of the most common technique for elimination of NOₓ. The promotional effect of Fe additive on the NH₃-SCR activity of the CeVO₄/TiO₂-graphene (GE) is systematically studied. The results exhibited that the low-temperature NOₓ conversion could be enhanced dramatically via the addition of Fe and Fe₀.₅Ce₀.₅VO₄/TiO₂-GE displayed the highest conversion of NOₓ in the wide temperature window (200–400 °C). It is because that Fe³⁺ + Ce³⁺ ↔ Fe²⁺ + Ce⁴⁺ facilitated the oxidization of NO to NO₂ at low temperature and led to the “Fast SCR,” thereby raising the SCR performance. What is more, the introduction of Fe enhanced redox ability, the surface relative percentage of Ce³⁺, V⁵⁺ and the chemical adsorbed oxygen. Furthermore, the high surface concentration of Ce³⁺ species can produce more active oxygen and leads to the “Fast SCR” reaction. In addition, the Fe₀.₅Ce₀.₅VO₄/TiO₂-GE catalyst showed excellent H₂O/SO₂ tolerance, which may be due to the decomposition of ammonium bisulphite under high temperature and the hydrophobicity of graphene. What is more, it displayed outstanding the stability. This work would provide theoretical reference for the practical application of NOₓ abatement via NH₃-SCR.
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