Effect of M-Doped (M = Cr, Fe, Co, and Nb) V2O5/TiO2(001) on Mercury Oxidation: The Insights from DFT Calculation

Modification of vanadium-based selective catalytic reduction (SCR) catalysts by transition metal allows for the design of wide temperature range catalysts for mercury removal. In this paper, by doping V2O5 supported on the TiO2(001) surface with Cr, Fe, Co, and Nb, the effect of doping on Hg-0 oxidation is investigated based on DFT calculation. By analyzing electronic properties of doped models, as well as HCl and Hg-0 adsorption, it is concluded that the introduction of Cr, Fe, Co, and Nb did not significantly affect the oxidizability of VOx species toward H-g(0). However, the introduction of Fe promotes the formation of oxygen ions with strong oxidizability as new active sites for He oxidation. Additionally, the reaction energies and energy barriers for H-g(0) oxidization show that the undoped vanadium-based catalyst and Fe-doped vanadium-based catalyst are favorable at high temperature and low temperature, respectively.