Effect of KCl on the Selective Catalytic Reduction of NO with NH3 over Vanadia-Based Catalysts for Biomass Combustion

摘要

Effect of KCl on vanadia-based catalysts for selective catalytic reduction of NO with NH3 was investigated by means of BET and pore size distribution measurements, XRD, XPS, FTIR, and NO reduction measurements. The catalytic activity was found to decrease rapidly with increasing the amount of KCl addition at different reaction temperatures. When the molar ratio of K/V exceeded 2.0, most of the activity was lost. The presence of KCl caused the sintering of the catalysts as well as the decrease in the amount of V atoms and the change of V valence state at the catalyst surface. Based on the analysis of physical and chemical properties of the catalysts, the KCl-poisoning mechanism model of the vanadia-based SCR catalysts was proposed.