Ligand Engineering-Modulated Surface Active Site Number in Pt1Ag14 Nanoclusters to Boost Photocatalytic H2 Production

Abstract

Controlling the number of surface active sites on catalysts at the atomic level remains challenging. Herein, we synthesize two Pt1Ag14 nanoclusters share the same Pt1Ag14 framework but exposing different numbers of Ag sites, namely Pt1Ag14[P(Ph-p-OMe)3]7(SPh)6 (Pt1Ag14-1) and Pt1Ag14[P(Ph-p-OMe)3]6(SCH2CH2Ph)6 (Pt1Ag14-2). Pt1Ag14-2, which exposes two Ag sites owing to terminal phosphine detachment, exhibits a significantly higher H2 evolution rate of 891.6 μmol•g -1 •h -1 compared with 249.4 μmol•g -1 •h -1 for Pt1Ag14-1. Mechanistic studies reveal that ligand-induced activesite variation accelerates interfacial charge transfer and enhances H* adsorption on Ag sites.