Deactivation of V{sub}2O{sub}5/TiO{sub}2 commercial SCR catalyst

摘要

The effect of K{sub}2O and P{sub}2O5 addition on the acid sites of V{sub}2O{sub}5(WO{sub}3)/TiO{sub}2 catalyst and the. relationship to the selective reduction of NO with NH{sub}3 were investigated by infrared spectroscopy, NH{sub}3 chemisorption, and NO reduction measurements. The catalytic activity decreased with both K{sub}2O and P{sub}2O{sub}5 loading. The effect of phosphorus was much smaller compared with that of K{sub}2O. The acidity of Bronsted sites decreases largely upon K{sub}2O addition in parallel with the decrease. of SCR activity. Upon P{sub}2O{sub}5 addition, the Bronsted acid were newly formed. The results obtained amply that the deactivation might be caused by a change in the nature of the hydroxyl groups acting as Bronsted acidsites.