Engineering the Electronic Structure of Submonolayer Pt on Intermetallic Pd 3 Pb via Charge Transfer Boosts the Hydrogen Evolution Reaction

The efficient electrochemical hydrogen evolution reaction (HER) plays a key role in accelerating sustainable H 2 production from water electrolysis, but its large-scale applications are hindered by the high cost of the state-of-the-art Pt catalyst. In this work, submonolayer Pt was controllably deposited on an intermetallic Pd 3 Pb nanoplate (AL-Pt/Pd 3 Pb). The atomic efficiency and electronic structure of the active surface Pt layer were largely optimized, greatly enhancing the acidic HER. AL-Pt/Pd 3 Pb exhibits an outstanding HER activity with an overpotential of only 13.8 mV at 10 mA/cm 2 and a high mass activity of 7834 A/g Pd+Pt at −0.05 V, both largely surpassing those of commercial Pt/C (30 mV, 1486 A/g Pt ). In addition, AL-Pt/Pd 3 Pb shows excellent stability and robustness. Theoretical calculations show that the improved activity is mainly derived from the charge transfer from Pd 3 Pb to Pt, resulting in a strong electrostatic interaction that can stabilize the transition state and lower the barrier.