Effect of HCl from municipal solid waste (MSW) on V2O5/AC (activated coke) catalyst for selective catalytic reduction (SCR) of NO with NH3 at low temperature is investigated and characterized by TG, elemental analyses and XRD. Results demonstrate that lower concentration HCl is beneficial to the activity of V2O5/AC catalyst; At the presence of HCl, the catalytic activity increases as the reaction temperature, and as the volume space velocity increases the catalytic activity decreases gradually. In the optimal reaction conditions of temperature above 120 degrees C and space velocity below 6000 h(-1), HCl plays a promoting effect on the catalytic activity of V2O5/AC catalyst. The promoting effect of HCl may be attributed to NH4Cl deposited on the catalyst surface, which can increase the surface acidity of the V2O5/AC catalyst and thus enhance the SCR activity. (C) 2014 Elsevier B.V. All rights reserved.