Improving the denitration performance and K-poisoning resistance of the V2O5-WO3/TiO2 catalyst by CO4+ and Zr4+ co-doping

A series of V2O5-WO3/TiO2-CeO2-ZrO2, V2O5-WO3/TiO2-CeO2-ZrO2, and V2O5-WO3/TiO2-CeO2-ZrO2 catalysts were synthesized to improve the selective catalytic reduction (SCR) performance and the K-poisoning resistance of a V2O5-WO3/TiO2 catalyst. The physicochemical properties were investigated by using XRD, BET, NH3-TPD, H-2-TPR, and XPS, and the catalytic performance and K-poisoning resistance were evaluated via a NH3-SCR model reaction. Ce4+ and Zr4+ co-doping were found to enhance the conversion of NOx, and exhibit the best K-poisoning resistance owing to the largest BET-specific surface area, pore volume, and total acid site concentration, as well as the minimal effects on the surface acidity and redox ability from K poisoning. The V2O5-WO3/TiO2-CeO2-ZrO2 catalyst also presents outstanding H2O + SO2 tolerance. Finally, the in situ DRIFTS reveals that the NH3-SCR reaction over the V2O5-WO3/TiO2-CeO2-ZrO2 catalyst follows an L-H mechanism, and that K poisoning does not change the reaction mechanism. (C) 2019, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.