Remarkably improved performance of Au-Pd/γ-Al2O3 catalyst in benzyl alcohol oxidation by mercapto-propyl-trimethoxysilane modification.

A series of γ-Al 2 O 3 supported gold-palladium (Au-Pd) alloy nanoparticles (NPs) catalysts were synthesized by a one-pot approach applying mercapto-propyl-trimethoxysilane (MPTMS) as an anchoring ligand. Homogeneously dispersed Au-Pd alloy NPs were observed on the prepared catalysts and their catalytic performance in benzyl alcohol partial oxidation was investigated. Results showed that the highest benzaldehyde yield was achieved on catalyst Au-Pd/7%MPTMS-γ-Al 2 O 3 with a benzaldehyde selectivity of 90%. By establishing the structure-performance relationship, the high activity of catalysts with MPTMS modification was attributed to the anchoring and dispersion effect of MPTMS on Au-Pd NPs, while the high benzaldehyde selectivity was due to the formation of more surface Lewis acid sites after introducing MPTMS, protecting the benzaldehyde from over-oxidation to byproducts. [Display omitted] • The presence of MPTMS led to well-dispersed Au-Pd alloy nanoparticles on alumina support. • The introduction of MPTMS produced more surface Lewis acid sites. • Lewis acid sites interacted with benzaldehyde, inhibiting over-oxidation and achieving high benzaldehyde selectivity. [ABSTRACT FROM AUTHOR]