Promoting electrochemical ammonia synthesis by synergized performances of MoC-MoN heterostructure.

Hydrogen has become an indispensable aspect of sustainable energy resources due to depleting fossil fuels and increasing pollution. Since hydrogen storage and transport is a major hindrance to expanding its applicability, green ammonia produced by electrochemical method is sourced as an efficient hydrogen carrier. Several heterostructured electrocatalysts are designed to achieve significantly higher electrocatalytic nitrogen reduction (NRR) activity for electrochemical ammonia production. In this study, we controlled the nitrogen reduction performances of MoC-MoN heterostructure electrocatalyst prepared by a simple one pot synthesis method. The prepared MoC-MoN heterostructure nanocomposites show clear phase formation for MoC and MoN, respectively. The prepared MoC-MoN electrocatalysts deliver a maximum ammonia yield of about 9.6 μg h cm and a Faradaic efficiency (FE) of about 10.15%. The study reveals the improved nitrogen reduction performances of MoC-MoN electrocatalysts due to the combined activity of the MoC and MoN phases. In addition, the ammonia production from MoC-MoN electrocatalysts is intended by the associative nitrogen reduction mechanism on MoC phase and by Mars-van-Krevelen mechanism on MoN phase, respectively. This study suggests the importance of precisely tuning the electrocatalyst by heterostructure strategy to substantially achieve higher nitrogen reduction electrocatalytic activity.