High Turnover Frequency in the Electrocatalytic Reduction of Nitrous Oxide to Dinitrogen at a Binuclear Copper Complex of 3,5‐Diamino‐1,2,4‐Triazole

Nitrous oxide (N₂O) is a potent greenhouse gas and an ozone-depleting substance. Electrocatalytic N₂O reduction (e-N₂ORR) is a promising approach to remove N₂O from the air under ambient conditions. However, developing noble-metal-free e-N₂ORR electrocatalysts with high Faradaic efficiency (FE) and turnover frequency (TOF) remains a challenge because of the weak binding of N₂O and the high kinetic barrier for deoxygenation reaction. In this work, inspired by the multinuclear copper active site of nitrous oxide reductases, a binuclear copper complex of 3,5-diamino-1,2,4-triazole supported on carbon black of Ketjenblack (CuHdatrz/KB) was utilized for the e-N₂ORR at pH 13 and 298 K. CuHdatrz/KB achieves a high FE of ≈ 100% at -0.3 V versus reversible hydrogen electrode for the e-N₂ORR to N₂ and TOF up to ≈ 700 h^-1, which is one-two orders of magnitude higher than those of the previously reported molecular-based catalysts. In situ X-ray absorption spectroscopy confirmed that Cu(II) ions of CuHdatrz/KB are reduced to Cu(I) keeping the binuclear core, suggesting that the multinuclear copper active site is crucial to efficiently catalyze the e-N₂ORR like the nitrous oxide reductase.