AUTHOR=An Tae-Yong , Surendran Subramani , Jesudass Sebastian Cyril , Lee Hyunjung , Moon Dae Jun , Kim Jung Kyu , Sim Uk 

TITLE=Promoting electrochemical ammonia synthesis by synergized performances of Mo2C-Mo2N heterostructure

JOURNAL=Frontiers in Chemistry

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1122150

DOI=10.3389/fchem.2023.1122150

ISSN=2296-2646

ABSTRACT=<p>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 Mo<sub>2</sub>C-Mo<sub>2</sub>N heterostructure electrocatalyst prepared by a simple one pot synthesis method. The prepared Mo<sub>2</sub>C-Mo<sub>2</sub>N<sub>0.92</sub> heterostructure nanocomposites show clear phase formation for Mo<sub>2</sub>C and Mo<sub>2</sub>N<sub>0.92</sub>, respectively. The prepared Mo<sub>2</sub>C-Mo<sub>2</sub>N<sub>0.92</sub> electrocatalysts deliver a maximum ammonia yield of about 9.6 μg h<sup>-1</sup> cm<sup>-2</sup> and a Faradaic efficiency (FE) of about 10.15%. The study reveals the improved nitrogen reduction performances of Mo<sub>2</sub>C-Mo<sub>2</sub>N<sub>0.92</sub> electrocatalysts due to the combined activity of the Mo<sub>2</sub>C and Mo<sub>2</sub>N<sub>0.92</sub> phases. In addition, the ammonia production from Mo<sub>2</sub>C-Mo<sub>2</sub>N<sub>0.92</sub> electrocatalysts is intended by the associative nitrogen reduction mechanism on Mo<sub>2</sub>C phase and by Mars-van-Krevelen mechanism on Mo<sub>2</sub>N<sub>0.92</sub> phase, respectively. This study suggests the importance of precisely tuning the electrocatalyst by heterostructure strategy to substantially achieve higher nitrogen reduction electrocatalytic activity.</p>