Electrostatic interaction tuned proton migration behavior by electron-rich Pt sites enhancing alkaline hydrogen evolution reaction

Regulating the critical process of proton migration from water dissociation for boosting alkaline hydrogen evolution reaction (HER) remains a challenge. Herein, we propose an electrostatic attraction strategy to achieve the migration of a highly efficient hydrogen species to Pt sites over Pt/Co@NC, which is obtained through a facile calcination and electrodeposition method. It exhibits an outstanding geometric activity (η10 = 31 mV), which surpasses the commercial 20 wt% Pt/C (η10 = 37 mV). Moreover, the mass activity of Pt/Co@NC is 5.6 A mgPt−1 at −50 mV vs. RHE, which is 2.23 times higher than that of 20 wt% Pt/C. Experimental and theoretical results indicate that the work function of the outer carbon layer, which is changed by the introduction of the inner cobalt core, plays a crucial role in reversing the direction of electron migration between the carbon layer and Pt. The negatively charged Ptδ− can spontaneously attract positively charged protons via the electrostatic interaction effect, thereby achieving the directional migration of hydrogen species. This work presents a strategy for designing advanced alkaline HER electrocatalysts by the electrostatic effect.