Efficient Electrocatalytic N2 Fixation with MXene under Ambient Conditions

Summary The current efficiency of NH 3 electrosynthesis from N 2 and H 2 O is ultralow as a result of poor selectivity in most catalysts. Here, we demonstrate that under ambient conditions, MXene (Ti 3 C 2 T x ) nanosheets attached to a vertically aligned metal host can achieve a high faradic efficiency (5.78%) at an ultralow potential for NH 3 electrosynthesis. On the basis of experimental and theoretical evidence, the basal plane of MXene is relatively inert, and its higher activity is related to a greater number of exposed edge sites. This work elucidates that significantly improved selectivity of NH 3 electrosynthesis can be achieved by tuning active sites and retarding hydrogen evolution activity. The proposed strategy provides a new opportunity to optimize the surface properties of 2D catalysts for efficient N 2 fixation under ambient conditions.