The electrochemical nitrogen reduction reaction (e-NRR) under ambient conditions is an emerging strategy used to tackle the hydrogen- and energy-intensive processes entailed in industrial ammonia (NH3) synthesis via the traditional Haber-Bosch process. However, e-NRR performance is currently impeded by the inherent inertness of N2 molecules, extremely slow kinetics, and overwhelming competition from the hydrogen evolution reaction (HER), all of which result in an unsatisfactory yield and ammonia selectivity.