Effect of metal oxide partial substitution of V2O5 in V2O5-WO3/TiO2 on selective catalytic reduction of NO with NH3

After partial substitution of V2O5 in V2O5-WO3/TiO2 by metal oxide (MA, M = Fe, Co, Ni, Cu, Sr, La, and Ce), the NO conversions for the MxOy-V2O5-WO3/TiO2 catalysts (M-VW) showed the following sequence: Co-VW > Fe-VW > Sr-VW approximate to Ce-VW approximate to La-VW > VW > Ni-VW > Cu-VW. The reduction activities for almost all the M-VW catalysts were enhanced at reaction temperature >400 degrees C, but only the Co-VW catalyst showed an increased activity at temperature <400 degrees C. Among the M-VW catalysts tested, the Co-VW sample had the highest catalytic activity with a temperature range of 300-550 degrees C for more than 90% NO removal at a GHSV of 60 000 h(-1). Moreover, the Co-VW sample exhibited high space-velocity, H2O and SO2 resistance, and low N2O yield. Co partial substitution for V in the VW led to more Lewis acid sites and Bronsted acid sites, and an obvious increase in the ratio of the adsorbed oxygen to the lattice oxygen from 12.74% for VW to 36.73% for Co-VW. The increased adsorbed oxygen and Lewis and Bronsted acid sites contributed to the improved SCR activity of the Co-VW sample. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.