Electrocatalytic Self-Coupling of N-Heterocyclic Amides for Energy-Efficient Bipolar Hydrogen Production

Abstract This study proposes a green electrochemical strategy for addressing the high-energy-barrier oxygen evolution reaction (OER) in traditional overall water splitting. Leveraging the thermodynamic advantages of N–H bond activation/cleavage and N–N coupling processes, the 3,5-diamino-1,2,4-triazole (DAT) oxidative coupling reaction (DATOR) has been introduced to replace the high-energy-barrier oxygen evolution reaction (OER). This substitution enables low-energy-consumption hydrogen production while simultaneously yielding high-value azo energetic materials. Furthermore, to enhance electron and atom economy, the anodic DATOR process allows the hydrogen radicals (H*) generated from amine dehydrogenation to chemically combine via the Tafel process, producing hydrogen gas. By constructing coupling system with Pt s,n @NiS 2 @CC cathode and CuO/CF anode, the operating voltage of the system was significantly reduced (0.96 V@10 mA cm − 2 ), which was 680 mV more energy efficient than conventional water electrolysis (1.64 V). In situ spectroscopy and theoretical calculations indicate that the anode DATOR generates DAAT through the N–H bond cleavage and N–N coupling path mediated by hydroxyl radicals (OH*), while releasing hydrogen gas. The coupling system has been operating stably for more than 300 h at an industrial-grade current density. This research provides new ideas for dual-electrode hydrogen production and green electrosynthesis of functional materials, with significant energy and economic benefits.