Fine Tuning Electronic Structure of Catalysts through Atomic Engineering for Enhanced Hydrogen Evolution

An efficient, durable, and low-cost hydrogen evolution reaction (HER) catalyst is an essential requirement for practical hydrogen production. Herein, an effective approach to facilitate the HER kinetics of molybdenum carbide (Mo2C) electrocatalysts is presented by tuning its electronic structure through atomic engineering of nitrogen implantation. Starting from the organoimido-derivatized polyoxometalate nanoclusters with inherent Mo-N bonds, the formation of N-implanted Mo2C (N@Mo2C) nanocrystals with perfectly adjustable amounts of N atoms is demonstrated. The optimized N@Mo2C electrocatalyst exhibits remarkable HER performance and good stability over 20 h in both acid and basic electrolytes. Further density functional theory calculations show that engineering suitable nitrogen atoms into Mo2C can regulate its electronic structure well and decrease Mo-H strength, leading to a great enhancement of the HER activity. It could be believed that this ligand-controlled atomic engineering strategy might influence the overall catalyst design strategy for engineering the activation sites of nonprecious metal catalysts for energy conversions.