Exploiting Anti-site Defects in FeWN2 Nanosheets for Enol Electrooxidation Coupled with H2 Evolution at a Large Current Density.

Hydrogen production from biomass electrooxidation offers a promising alternative to water electrolysis by lowering the anodic oxidation barrier and producing valuable chemicals. However, current biomass electrooxidation systems have difficulties in achieving an industrial-scale current density due to the difficulty in cleaving high-energy C-H and O-H bonds. Here, we report a ternary layer nitride FeWN2 electrocatalyst with abundant anti-site defects (ASDs), which significantly improves its electrocatalytic performance for ascorbic acid (AA) oxidation. The catalyst works at a remarkable current density of 2.5 A cm-2 at 0.69 V (vs. RHE) and achieves 4 A cm-2 at 1.12 V in a two-electrode electrolyzer at 60°C with 100% Faraday efficiency for H2 production. Theoretical calculations reveal that W atoms near antipodal Fe sites replenish the electron density of Fe, maintaining moderate Fe-DHA adsorption strength induced by ASDs that achieve superior catalytic efficiency for AA-to-DHA conversion This study provides new insight for developing high-performance organic oxidation catalysts with ASDs.