Electrocatalytic Reduction of Nitrogen to Ammonia Using Tiara‐like Phenylethanethiolated Nickel Cluster

Abstract The fixing of N 2 to NH 3 is challenging due to the inertness of the N≡N bond. Commercially, ammonia production depends on the energy‐consuming Haber‐Bosch (H−B) process, which emits CO 2 while using fossil fuels as the sources of hydrogen and energy. An alternative method for NH 3 production is the electrochemical nitrogen reduction reaction (NRR) process as it is powered by renewable energy sources. Here, we report a tiara‐like nickel‐thiolate cluster, [Ni 6 (PET) 12 ] (where, PET=2‐phenylethanethiol)] as an efficient electro‐catalyst for the electrochemical NRR at ambient conditions. Ammonia (NH 3 : 16.2±0.8 μg h −1 cm −2 ) was the only nitrogenous product over the potential of −2.3 V vs . F c + /F c with a Faradaic efficiency of 25%±1.7. Based on theoretical calculations, NRR by [Ni 6 (PET) 12 ] proceeds through both the distal and alternating pathways with an onset potential of −1.84 V vs . RHE (i.e., −2.46 V vs . F c + /F c ) which corroborates with the experimental findings.