Nitrogen-doped carbon coated NiFeNxnanosheet arrays for efficient glycerol electrooxidation coupled with hydrogen evolution.

Abstract

Water splitting represents a pivotal technology for green hydrogen generation, yet its practical application remains constrained by the sluggish kinetics of the oxygen evolution reaction (OER). To address this challenge, we propose a hybrid electrolysis system that replaces OER with the thermodynamically favorable glycerol oxidation reaction, thereby enabling energy-efficient hydrogen production coupled with value-added chemical synthesis. In this work, we reported a bifunctional self-supporting electrocatalyst for the growth of nitrogen-doped carbon shell NiFeN_xnanosheets on carbon fibers (NC@NiFeN_x) that can be applied to efficient hydrogen production and formate generation. The system can be achieved with a cell voltage of only 1.38 V at 10 mA cm^-2, which is lower than the overall water electrolysis (1.70 V). Notably, the system achieves exceptional Faradaic efficiencies of 99.7% for hydrogen evolution and 95% for formate generation. This work establishes an innovative strategy for co-producing H₂and valuable chemicals through glycerol valorization, while addressing key energy challenges in conventional water electrolysis.