Computational study of tailorable metal–support interactions in PtSn/γ-Al2O3via surface hydroxylation†

Abstract

Metal–support interactions (MSIs) are fundamental to the design and optimization of heterogeneous catalysts. In PtSn/γ-Al₂O₃ catalysts, the tunable surface properties of γ-Al₂O₃ provide opportunities to tailor MSIs for optimal catalytic performance, and calls for extensive study on the influence of surface hydroxylation of γ-Al₂O₃ on MSIs. Herein, the influence of the surface hydroxylation mode and hydroxyl coverage on MSIs was investigated, and the results show that terminal hydroxyl groups can bind with the PtSn cluster to assist the anchoring of the cluster, while bridging hydroxyl groups repel the cluster from accessing the surface. A positive correlation between the Pt 5d band center and the support-to-metal charge transfer was established, and the charge of the supported metal cluster was proposed to be used as a descriptor to evaluate its reactivity in a catalytic reaction. This study provides insight into the rational design of tailored catalysts supported on hydroxylated surfaces.