PECULIAR RESPONSE OF V2O5-WO3/TiO2 DENOX CATALYSTS TO THERMAL STRESS - AN STUDY WITH CATALYTIC AND SPECTROSCOPIC TOOLS

摘要

Background SCR with ammonia is a proven technology for NOx abatement from stationary sources, and the V2O5- WO3/TiO2 catalysts employed are considered well-studied and mature. It has been reported in the literature [1] that treatment at high temperatures may improve their catalytic performance, though at the expense of an enhanced N2O production, probably caused by increased formation of highly active surface polyvanadate species. We report here a detailed study on the response of the V2O5-WO3/TiO2 system to high-temperature stress. It will be shown that with decreasing BET surface area the activity goes through up to three distinct maxima before decaying finally, which cannot be explained by the simple assumption mentioned above.