Mo ₂ C/MoB/MoN Composite Ceramic Electrode with High Catalytic Activity and Stability for Hydrogen Evolution Reaction at High Current Density of Industrial Grade

In response to the growing demand for industrial-scale hydrogen production via water electrolysis, we report a Mo2C/MoB/MoN multiphase ceramic electrode exhibiting both high catalytic activity and exceptional stability. A Mo2C/MoB composite ceramic membrane was first fabricated via phase-inversion tape casting, followed by reaction sintering using Mo2C and B4C powders, and subsequently subjected to nitridation in an NH3 atmosphere to form the final Mo2C/MoB/MoN electrode. The electrode features abundant in-situ-formed heterostructures, including Mo2C (101)/MoB (103), MoB (103)/MoN (200), and Mo2C (100)/MoN (200), accompanied by a high density of structural defects. These characteristics enable highly efficient hydrogen evolution in alkaline media, achieving a current density of 1500 mA cm–2 at an overpotential of only 265 mV, surpassing the performance of commercial platinum electrodes under similar conditions. Chronoamperometric measurements over a wide current density range (50–1500 mA cm–2) demonstrate outstanding catalytic durability and structural integrity, with stable operation exceeding 252 h. Density functional theory (DFT) calculations reveal that the MoB (103)/MoN (200) heterostructure provides a favorable energy barrier for water dissociation, while Mo2C (101)/MoB (103) exhibits near-optimal hydrogen adsorption free energy. The spatial separation of water dissociation and hydrogen adsorption/desorption on adjacent active sites, together with their synergistic interaction, significantly enhances the overall catalytic performance.