Inhibition effect of HBr over a commercial V2O5-WO3/TiO2 catalyst in a NH3-SCR process

Although HBr promotes Hg-0 oxidation over the V2O5-WO3/TiO2 catalyst, it possibly influences the catalyst DeNO(x) activity. NH3-SCR experiments were conducted over a commercial V2O5-WO3/TiO2 catalyst in the presence of HBr. NO conversion obviously decreases in the low temperature range (i.e., <300 degrees C). XPS analysis suggests that HBr reacted with the surface vanadium species, increasing the amount of Br species and V4+ species. In situ FTIR study reveals that HBr adsorbed on the catalyst surface and subsequently reacted with V=0 species which served as active sites in the SCR reaction, thus resulting in the inhibition effect for the DeNO(x) activity. (C) 2017 Elsevier B.V. All rights reserved.