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

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@NiS₂@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.