Electrocatalytic Conversion of 3,4-Diaminofurazan Coupled with Hybrid Water Electrolysis: A Synergistic Strategy for Sustainable Hydrogen Evolution

By making use of the thermodynamically favorable 3,4-diaminofurazan oxidation reaction (DOR) to replace the oxygen evolution reaction (OER), we developed a two-in-one system for the electrosynthesis of 3,3′-diamino-4,4′-azofurazan (DAAzF) energetic materials and the low-energy-consumption H2 production. This hybrid green electrosynthesis strategy avoids the use of strong oxidants and the generation of byproducts in the traditional DAAzF synthesis process. The HER||DOR coupled system can be operated at a low 1.29 V cell voltage at a current density of 10 mA cm–2, which is 280 mV lower than the traditional overall water electrolysis (OWS). Because of this unique advantage, the electricity consumption of the HER||DOR coupled system is reduced by 31.8% at a high current density of 50 mA cm–2. An anion-exchange membrane water electrolysis (AEMWE) can be stably operated at an industrial-level current density of 1.0 A cm–2 at 3.4 V for >100 h with a small degradation rate of 233 μV h–1. The density functional theory (DFT) calculations have revealed that the loaded Ru species help to regulate the local electronic properties of the CoSe2 surface, to form the Volmer–Heyrovsky HER pathway, and to improve the alkaline HER kinetics. The anodic DOR is triggered by OH* and proceeds with the stepwise dehydrogenation of the amino group in DAF substrates to form DAAzF. This work is a case study for the green electrosynthesis of azo energetic materials and energy-saving hydrogen production.