The effects of CO on the catalytic activities of Ag/AL(2)O(3) for NOs reduction by propane were investigated. Unlike on 1% Ag/AL(2)O(3), the significant promotion effect of CO was observed on Ag catalyst with higher Ag loading. The presence of CO obviously broadened the operation window of C3H8-SCR on 5% Ag/AL(2)O(3), and the temperature range was expanded from 425-510 degrees C to 375-545 degrees C. CO did not involve in NO reduction directly. In situ DRIFTS in different feed gases showed that the presence of CO promoted the partial oxidation of C3H8 on 5% Ag/Al2O3 and led to the obvious increases in the amount and variety of intermediate species of C3H8 partial oxidation, namely the enolic and acetate species, which promoted NOs removal significantly. (C) 2016 Elsevier B.V. All rights reserved.