Effect of pre-oxidation process on V2O5/AC catalyst for the selective catalytic reduction of NOx with NH3

Activated coke-based catalysts have attracted extensive attention in denitration by selective catalytic reduction by NH3 (NH3-SCR), due to their excellent catalytic performance at low temperature. In the paper, the V2O5/AC catalyst was prepared by the impregnation method to investigate the effect of pre-oxidation process on its NH3-SCR activity. Activity test results show that the V2O5/AC catalyst with 4-h pre-oxidation exhibits the best NOx removal efficiency, which reaches the NOx conversion is over 75% in the range of 200–240 °C and exhibits an excellent resistance to SO2 and H2O. Characterization results demonstrate that the V4+ was oxidized by oxygen molecule during pre-oxidation process, which contributes to the formation of V5+ ions and surface-active oxygen species. The surface-active oxygen species are conducive to promoting the “fast SCR” reaction; thus, the pre-oxidized process can contribute to the superior NH3-SCR performance for V2O5/AC catalyst at low temperature.