LAUSR

Abstract Well-dispersed Au-Pt (2–5 nm) and Au-Pd (1–5 nm) nanoparticles (NPs) supported on mesoporous silica (meso-SiO2) were prepared by a facile one-pot synthesis method using 3-mercapto(propyl)trimethoxysilane (MPTMS) to anchor metal NPs to the support. The obtained catalysts were characterized and evaluated in cyclohexane oxidation with molecular oxygen. The bimetallic NPs catalysts prepared in this work exhibited a high stability with enhanced dispersion because of the intercalation of the metal alloy NPs in the meso-SiO2 channels via the anchoring effect of MPTMS. The generation of surface Auδ− species in Au-Pt and Au-Pd catalysts was identified due to the alloying of Au with Pt and Pd. Although the electronic modification of Au atoms weakened the capability of Au for O2 activation and leads to lower cyclohexane conversions on bimetallic catalysts, the deep oxidation reactions were reduced and a higher selectivity of desired products, K/A oil (cyclohexanol and cyclohexanone) was achieved. This work demonstrates an effective preparation method to improve the stability and surface chemical modification of Au NP catalysts, which provides general implications for other noble metal NPs catalysts.