Oxidation of carbon monoxide over palladium–tin(IV) oxide catalysts: an example of spillover catalysis

Pd–SnO2 catalysts are more active for CO oxidation than either Pd–SiO2 or SnO2, but are relatively inactive for C2H4 hydrogenation; grinding of Pd–SiO2 and SnO2 mixtures enhances CO oxidation activity, indicating that Pd induces activity on the SnO2 surface.