Mesostructured cellular foam silica supported Au–Pt nanoalloy: Enrichment of d-state electrons for promoting the catalytic synergy

Abstract

A mesostructured cellular foam (MCF) silica was applied to support gold (Au) – platinum (Pt) alloy nanoparticles (NPs) for benzyl alcohol partial oxidation. A catalytic synergy on bimetallic gold (Au)-platinum (Pt) nanoparticle (NP) catalyst, referring to that introducing Au to Pt leading to a higher catalytic performance has been observed. However, the essence of this synergistic effect is still under debate. In this work, a series of MCF supported Au–Pt NP catalysts are designed to reveal the essence . Well-developed porous structure of MCF support eliminated the mass transfer limitation and intrinsic catalytic activity was obtained. The improved catalytic performance on bimetallic catalyst is attributed to the geometric and electronic changes of active sites after formation of Au–Pt alloy NPs. Compared with monometallic catalyst, the formation of Au–Pt alloy results in the changes of particle size and lattice structure. Electronic property analyses confirmed the increase of d state electrons on Au–Pt alloy NPs, which are calculated from s-p-d hybridization and intra-atomic charge redistribution, leading to the increased abundance of transferable d electrons near Fermi level and further enhancing the catalytic activity. These findings gain new insights into the catalytic synergy of bimetallic nanoparticles and shed light on the optimization of these catalysts. The catalytic synergy of mesostructured cellular foam silica supported bimetallic Au–Pt catalysts for benzyl alcohol oxidation is attributed to the increased abundance of transferable d electrons near Fermi level which are calculated from s-p-d hybridization and intra-atomic charge redistribution. • Mesostructured cellular foam silica support Au–Pt alloy nanoparticles were prepared by a facile one-pot method. • The formation of Au–Pt alloy nanoparticles results in particle size variation and lattice distortions. • Electron polarization leads to the increase of transferable d-orbital electrons on Au and Pt atoms. • The catalytic activity on Au–Pt alloy catalyst was enhanced through accelerating the O 2 activation.