High-temperature diffusion induced high activity of SBA-15 supported Ag particles for low temperature CO oxidation at room temperature

► O2 treatment at 900 °C induced more Ag atoms to diffuse into the channels of SBA-15. ► A 98% conversion of CO was achieved at 20 °C over 1.42 wt% Ag/SBA-15. ► Catalytic activity was related to the restructuring and distribution of Ag particles. ► The channel of SBA-15 was effective for the stability of Ag particles. ► Ag+ formed on the surface at 900 °C was favorable for the following H2 reduction.