Regulation of organic molecule-water interface reactions: performance study of an aminotriazole electrooxidation-coupled bipolar hydrogen production system

Integrating thermodynamically-favorable small molecules oxidation with water electrolysis offers an effective way to realize energy-efficient H 2 production and obtain value-added chemicals as well. In this study, we report an energy-saving H 2 production system utilizing thermodynamically favorable 3,5-diamino-1 H -1,2,4-triazole (DAT) electrooxidation reaction (DATOR) as an oxygen evolution reaction-alternative process of low-energy-consumption for H 2 production. At the anode, value-added 3,3′-diamino-5,5′-azo-1,2,4-triazole (DAAT) energetic chemical and H 2 are obtained. The carbon cloth-loaded NiS 2 (CC@NiS 2 ) substrate and doped with Ru nanoparticles (NPs) cathode could modulate the electronic structure, resulting in a hydrogen evolution reaction (HER) overpotential as low as 34.4 mV at a current density of 10 mA cm −2 . Density Functional Theory calculations show that the synergistic effect of the Ru NPs and NiS 2 significantly enhanced the alkaline HER kinetics. Benefitting from the DATOR and high hydrogen atom economy to convert H of DAT substrate to H 2 via Tafel pathway, the assembled CC@NiS 2 /Ru NPs||CF@CuO NWs (CF: copper foam) two-electrode coupling system only requires 1.04 V to drive a current density of 10 mA cm −2 , and greatly reduces the energy consumption by 36.6% for H 2 production compared with conventional water electrolysis, avoiding the traditional hazardous synthesis condition of DAAT. Furthermore, anion-exchange membrane electrolyzer tests show superior long-term stability of 250 h at a high current density of 0.5 A cm −2 . This study not only provides a new idea for the sustainable electrosynthesis of energy-containing materials, but also demonstrates the broad application prospects of electrocatalytic coupling systems in the co-production of clean energy and high-value chemicals.