Plasma-Structured Molybdenum Oxycarbides Enabling Ultrastable Acidic Hydrogen Evolution up to 10 A cm-2

Fabricating electrocatalysts capable of stable operation at high current densities is crucial for the industrial proton exchange membrane water electrolysis. However, current catalysts suffer from high overpotentials and rapid degradation when working in acid electrolytes at high current densities. In this paper, we report the design of vertical-standing, nanoedge-enriched molybdenum oxycarbide electrocatalysts via plasma-enhanced chemical vapor deposition (PECVD) with salts as precursors to achieve outstanding acidic electrocatalytic hydrogen evolution performance. Benefiting from their unique structural features and chemical compositions, the plasma-grown molybdenum oxycarbide catalysts exhibit a low overpotential of 415 mV at industrial-level high current densities up to 10 A cm-2 for 1,000 h, corresponding to an ultrahigh hydrogen throughput of 4,477.4 L cm-2 and substantially surpassing the performance of state-of-the-art transition metal- and even noble metal-based catalysts. This work paves the way for the development of new transition metal-based catalysts for practical industrial electrocatalytic hydrogen evolution.