High-Performance Electrohydrogenation of N-2 to NH3 Catalyzed by Multishelled Hollow Cr2O3 Microspheres under Ambient Conditions

Electrohydrogenation of N-2 to NH3 is emerging as an environmentally benign strategy to tackle the issues associated with the energy-intensive, CO2-emitting Haber-Bosch process. However, the method is severely challenged by N-2 activation and needs efficient N-2 reduction reaction (NRR) catalysts. Here, we report that multishelled hollow Cr2O3 microspheres (MHCMs), which are synthesized by a facile synthetic route, can serve as efficient and selective non-noble metal electrocatalysts for NRR. In 0.1 M Na2SO4 solution, the MHCMs achieve a high Faradaic efficiency (6.78%) and a large NH3 yield (25.3 mu g h(-1) mg(cat)(-1)) at -0.9 V vs reversible hydrogen electrode. The MHCMs also exhibit high stability during the reaction. Density functional theory calculations suggest that NRR over MHCMs occurs via both distal associative and partially alternative routes.