Compatibility between Activity and Selectivity in Catalytic Oxidation of Benzyl Alcohol with Au–Pd Nanoparticles through Redox Switching of SnOx

A balance between catalytic activity and product selectivity remains a dilemma for the partial oxidation processes because the products are prone to be overoxidized. In this work, we report on the partial oxidation of benzyl alcohol using a modified catalyst consisting of nanosized Au-Pd particles (NPs) with tin oxide (SnO x ) deposited on a mesoporous silica support. We found that the SnO x promotes the autogenous reduction of PdO to active Pd 0 species on the Au-Pd NP catalyst (SnO x @AP-ox) before H 2 reduction, which is due to the high oxophilicity of Sn. The presence of active Pd 0 species and the enhancement of oxygen transfer by SnO x led to high catalytic activity. The benzaldehyde selectivity was enhanced with the increase of SnO x content on catalyst SnO x @AP-ox, which is ascribed to the modulated affinity of reactants and products on the catalyst surface through the redox switching of Sn species. After H 2 reduction, SnO x was partially reduced and Au-Pd-Sn alloy was formed. The formation of Au-Pd-Sn alloy weakened both the catalytic synergy of Au-Pd alloy NPs and the adsorption of benzyl alcohol on the reduced catalyst, thus leading to low catalytic activity.