Precision Electronic Tuning of Gold Nanoclusters: A Generalizable Strategy for Enhanced Hydrogen Evolution Electrocatalysis via Platinum Doping

Atomically precise gold nanoclusters hold promise in electrocatalysis, but postsynthetic electronic structure manipulation improves the hydrogen evolution reaction (HER). Herein, we develop a mild heterogeneous Pt doping strategy by substituting one Pt atom in [Au 8 (DPPP) 7 Cl 2 ] + (DPPP = 1,3-bis(diphenylphosphino)propane). The doped [Au 7 Pt(DPPP) 7 Cl 2 ] + retains the original ligand coordination and structural integrity as confirmed by ESI-MS, NMR, and TEM. Pt doping selectively modulates the electronic environment of reduction-active sites, evidenced by a 100 mV positive shift in reduction potential and Au 4f XPS binding energy elevation without altering oxidation-active metallic cores. This electronic reconfiguration optimizes H* adsorption energy, enabling exceptional HER performance: 0.22 V lower onset potential and 5.6-fold higher current density versus the undoped analog. [Au 7 Pt(DPPP) 7 Cl 2 ] + outperforms the undoped nanocluster and platinum on carbon (Pt/C), with higher double-layer capacitance (4.66 mF·cm –2 ), lower charge transfer resistance, excellent 24 h stability, and enhanced electrochemical active surface area, confirming practical HER potential. This work establishes heterogeneous metal atom doping as a generalizable approach for electronic fine-tuning of nanocluster catalysts.