Modulation of the surface active site number in Pt1Ag14 nanoclusters by ligand engineering 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 sharing the same Pt₁Ag₁₄ framework but exposing different numbers of Ag sites, 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 active-site variation accelerates interfacial charge transfer and enhances H* adsorption on Ag sites.