Insights into Tuning of Mo-Based Structures toward Enhanced Electrocatalytic Performance of Nitrogen-to-Ammonia Conversion

Ammonia is commonly produced via the Haber-Bosch process, which is energy intensive with emission of substantial greenhouse gases. As one alternative method, electrochemical nitrogen reduction reaction (NRR) can be driven by the renewable energy and realized at ambient conditions for sustainable NH3 synthesis. However, the reaction suffers from high overpotentials and low selectivity due to the potential overlap with competing proton reduction. As inspired by the natural nitrogenase enzymes, Mo sites are particularly investigated to exhibit the potential for catalyzing NRR. Herein, the recent progresses in modifying Mo-based catalysts toward enhanced NRR performance are discussed. The modification strategies vary from tuning of metal cores, coordination spheres, and assembled structures. The modification strategies can both efficiently tune the chemisorption energy and geometry of N-2, as well as hydrogenated N derivatives on the Mo sites.