Superior activity of CeO2 modified V2O5/AC catalyst for mercury removal at low temperature.

CeO 2 modified V 2 O 5 /AC catalysts (V-Ce/AC) were synthesized by an ultrasound-assisted impregnation method, and were employed to remove elemental mercury (Hg 0 ) from simulated coal combustion flue gas at low temperature (100–200 °C). The effects of several operation conditions, including the loading of CeO 2 , reaction temperature, the role of O 2 and stability of the catalysts were all investigated, respectively. The results showed that 1 V-8Ce/AC catalysts had the highest catalytic activity with 98.3% Hg 0 removal efficiency at 150 °C. There was synergistic effect on Hg 0 oxidation when V 2 O 5 and CeO 2 combined. Characterization by XPS, we found that both lattice oxygen (O α ) and chemisorption oxygen (O β ) contribute to Hg 0 oxidation. Besides, the possible mechanism of Hg 0 removal over the catalysts was proposed, in which the critical steps were the adsorption of Hg 0 and the oxidation of Hg 0 to Hg 2+ by the active oxygen on catalysts surface. [ABSTRACT FROM AUTHOR]