The effect of Ag and CeO₂ distribution on SBA-15 surface on the activity of Ag–CeO₂/SBA-15 catalysts in CO and methanol oxidation

The series of catalysts representing the mesoporous ordered silica SBA-15 with supported silver or silver and ceria nanoparticles were synthesized by incipient wetness impregnation, characterized by the low-temperature N ₂ adsorption, XRD, TEM HR, TPR-H ₂ methods, and tested in the low-temperature CO oxidation and total oxidation of methanol. It was found that two types of silver particles are formed: small particles (<3 nm) inside the pores of the SBA-15 and larger particles (3–15 nm) on the external surface of SBA-15. High activity of the prepared catalyst in oxidation of CO and methanol is attributed to both small sizes of silver particles and the Ag–CeO ₂ interaction. The distribution of both silver and ceria on the SBA-15 surface determines their interaction and, hence, enhances the catalytic activity in oxidative reactions due to the cooperation of active oxidative sites of silver and ceria at the Ag–CeO ₂ interface. [Figure not available: see fulltext.]