MoO3 nanosheets for efficient electrocatalytic N-2 fixation to NH3

The synthesis of NH3 heavily depends on the energy-intensive Haber-Bosch process with a large amount of greenhouse gas emission. Electrochemical reduction offers a carbon-neutral process to convert N-2 to NH3 at ambient conditions, but requires efficient and stable catalysts for the N-2 reduction reaction. Mo-dependent nitrogenases and synthetic molecular complexes have attracted increasing attention for N-2 fixation; however, less attention has been paid to Mo-based nanocatalysts for electrochemical N-2 conversion to NH3. Herein, we report that MoO3 nanosheets act as an efficient non-noble-metal catalyst for electrochemical N-2 fixation to NH3 with excellent selectivity at room temperature and atmospheric pressure. In 0.1 M HCl, this catalyst exhibits remarkable NRR activity with an NH3 yield of 4.80 x 10(-10) mol s(-1) cm(-2) (29.43 g h(-1) mg(cat.)(-1)) and a faradaic efficiency of 1.9%. Moreover, this catalyst also shows high electrochemical stability and durability. Density functional theory calculations reveal that the outermost Mo atoms serve as the active sites for effective N-2 adsorption.