Strategic Design of MoO2 Nanoparticles Supported by Carbon Nanowires for Enhanced Electrocatalytic Nitrogen Reduction

Ammonia is an industrially relevant chemical that can be directly synthesized from water and air using renewable energy through the electrochemical nitrogen reduction reaction (NRR). However, because of the inert nature of nitrogen, current attempts at synthesizing ammonia under aqueous conditions result in low selectivity and yield rates. The poor electrocatalytic performance is mainly attributed to competing hydrogen evolution, underexposed active sites, inadequate electrode contact, and poor stabilization/destabilization of key reaction intermediates. Herein, we present a catalyst composed of MoO2 with surface vacancies dispersed over conductive carbon nanowires that mitigates these obstacles for NRR by providing a high surface area with stable catalytic sites and an underlying conductive support, where a variety of X-ray spectroscopy techniques are used to characterize the MoO2 catalyst. This uniquely engineered catalyst exhibits exceptional Faradaic efficiencies of over 30% and yields of 21.2 μg h–1 mg–1 at a low potential of −0.1 V vs RHE under ambient aqueous conditions.