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

Abstract

Although HBr promotes Hg0 oxidation over the V2O5-WO3/TiO2 catalyst, it possibly influences the catalyst DeNOx 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°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=O species which served as active sites in the SCR reaction, thus resulting in the inhibition effect for the DeNOx activity.