Engineering Oriented Pt Deposition via Micro-Nano Crisscross Scaffolds: A Paradigm for High-Efficiency HER Catalyst.

A critical issue for the hydrogen evolution reaction (HER) is to break the inherent trade-off between catalytic activity and mass/charge transport in platinum-based electrocatalysts. In this work, inspired by the hierarchical coupling of vascular and neural networks in biological systems, we report a high-performance HER electrocatalyst consisting of platinum nanoparticles anchored on crisscross carbon micro-nanostructures (CCMN). The 3D scaffold simultaneously accelerates charge delivery, proton supply, and hydrogen bubble detachment, thus alleviating key limitations in the electrode process. The Pt/WC/CCMN (2 wt%) catalyst was prepared via controlled carburization of a W-doped Fe-BTC precursor, followed by selective Pt deposition through galvanic replacement. Electrochemical measurements reveal that the catalyst delivers 100 mA cm-2 at an overpotential of only 49 mV. H2 bubbles formed on the Pt/WC/CCMN electrode are relatively large and detach easily from the surface. Notably, Pt/WC/CCMN exhibits a turnover frequency value of 27.16 H2 s-1 at 100 mV, 3.6 times higher than that of commercial Pt/C (7.41 H2 s-1). This work develops a competitive HER electrocatalyst and also provides a universal design strategy for gas-involved electrocatalytic reactions.