Effect of KCl on selective catalytic reduction of NO with NH3 over a V2O5/AC catalyst

Deactivation of a low temperature selective catalytic reduction (SCR) catalyst, 1 wt% V2O5/AC, by potassium chloride (KCl) is studied using BET and pore size distribution measurements, NH3 sorption and temperature-programmed desorption (TPD), temperature-programmed surface reaction (TPSR). Results show that KCl deactivates 1 wt%V2O5/AC’s SCR activity and the deactivation become severer at higher KCl loadings. The deactivation is not caused by pore plugging but by neutralization of acid sites on V2O5/AC. Weak acid sites are responsible for NH3 activation and SCR of NO, and are preferentially deactivated by KCl.