The in situ decoration of Ti 3 C 2 quantum dots on Cu nanowires for highly efficient electrocatalytic reduction of nitric oxide to ammonia

In order to solve the environmental problems caused by the ever-growing NO emission from the combustion of fossil fuels, an electrocatalytic reduction technique has been developed to convert NO into NH 3 under ambient conditions, which is also regarded as a promising alternative for the traditional Haber–Bosch process. Catalysts with excellent activity and selectivity are necessary for the efficient NO reduction to NH 3 . Herein, we decorated Ti 3 C 2 quantum dots (Ti 3 C 2 QDs) on Cu nanowires (Cu NWs) as an efficient and stable electrocatalyst (Ti 3 C 2 QDs/Cu NWs) with greatly improved NO conversion performances. The Ti 3 C 2 QDs/Cu NWs affords a significantly enhanced NH 3 yield of 5346.3 μg h −1 mg −1 and high faradaic efficiency (FE) of 95.5% compared to the Cu NWs (3313.11 μg h −1 mg −1 , 89.51%) at −0.4 V vs. RHE in 0.1 M K 2 SO 4 electrolyte. We further assembled a Zn–NO battery using Ti 3 C 2 QDs/Cu NWs as the cathode and a Zn plate as the anode, which shows a power density of 3.03 mW cm −2 and an NH 3 yield of 925.2 μg h −1 mg −1 . The improved NORR activity can be attributed to the role of the Ti 3 C 2 QDs converter. The density functional theory calculation results reveal the catalytic mechanism, indicating the reaction pathway of *NO → *HNO → *N → *NH → *NH 2 → *NH 3 and the potential determination step of *N → *NH.