Inducing a Synergistic Effect on Pt^δ+/Electron-Rich Sites via a Platinization Strategy: Generating Hyper-High Current Density in Hydrogen Evolution Reaction

Herein, we propose a platinization strategy for the preparation of Pt/X catalysts with low Pt content on substrates possessing electron-rich sites (Pt/X: X = Co₃O₄, NiO, CeO₂, Covalent Organic Framework (COF), etc.). In examples with inorganic and organic substrates, respectively, Pt/Co₃O₄ possesses remarkable catalytic ability toward HER, achieving a current density at an overpotential of 500 mV that is 3.22 times higher than that of commercial Pt/C. It was also confirmed by using <i>operando</i> Raman spectroscopy that the enhancement of catalytic activity was achieved after platinization of the COF, with a reduction of overpotential from 231 to 23 mV at 10 mA cm^-2. Density functional theory (DFT) reveals that the improved catalytic activity of Pt/Co₃O₄ and Pt/COF originated from the re-modulation of Pt^δ+ on the electronic structure and the synergistic effect of the interfacial Pt^δ+/electron-rich sites. This work provides a rapid synthesis strategy for the synthesis of low-content Pt catalysts for electrocatalytic hydrogen production.