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

Abstract

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 Mo2C-Mo2N heterostructure electrocatalyst prepared by a simple one pot synthesis method. The prepared Mo2C-Mo2N0.92 heterostructure nanocomposites show clear phase formation for Mo2C and Mo2N0.92, respectively. The prepared Mo2C-Mo2N0.92 electrocatalysts deliver a maximum ammonia yield of about 9.6 μg h-1 cm-2 and a Faradaic efficiency (FE) of about 10.15%. The study reveals the improved nitrogen reduction performances of Mo2C-Mo2N0.92 electrocatalysts due to the combined activity of the Mo2C and Mo2N0.92 phases. In addition, the ammonia production from Mo2C-Mo2N0.92 electrocatalysts is intended by the associative nitrogen reduction mechanism on Mo2C phase and by Mars-van-Krevelen mechanism on Mo2N0.92 phase, respectively. This study suggests the importance of precisely tuning the electrocatalyst by heterostructure strategy to substantially achieve higher nitrogen reduction electrocatalytic activity.

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

“…Such superior diffusion characteristics are necessary to enhance the catalytic performance of an electrocatalyst, especially in complex reactions such as the electrochemical NRR. Therefore, our findings provide valuable insights for the design and development of highly efficient electrocatalysts for NRR and related applications , …”

“…Such superior diffusion characteristics are necessary to enhance the catalytic performance of an electrocatalyst, especially in complex reactions such as the electrochemical NRR. Therefore, our findings provide valuable insights for the design and development of highly efficient electrocatalysts for NRR and related applications 50,51 The stability of the catalyst is a crucial feature that determines its potential for large-scale industrial use. Therefore, the stability of the catalyst was tested over 15 h at a potential of −0.1 V vs RHE, Figure S13.…”

Boosting the Faraday Efficiency of Electrochemical Ammonia Synthesis via the Strain Effect Induced by Interfacial Hybrid Formation between BN and Carbon Nanotubes

“…The h-BNNs was obtained in the liquid phase exfoliation method via ultra-sonication, as shown in Figure S2, the prepared h-BNNs shows a distinct lamellar structure. 47 When the obtained h-BNNs and acid-treated CNTs were sonicated together, a nanocomposite of h-BNNs/CNTs with different mass ratios (x% h-BNNs/CNTs) were obtained, as shown in Figure 1a. Figure 1b,c show the representative transmission electron microscopy (TEM) image of the obtained 68.6% h-BNNs/CNTs.…”

Investigating the role of oxygen vacancies in metal oxide for enhanced electrochemical reduction of NO3− to NH3: mechanistic insights

“…7,8 Recently, considerable research efforts have been dedicated to investigating diverse innovative methods for electrochemically reducing N 2 to produce NH 3 . [9][10][11][12][13] However, the process continues to face challenges in terms of low yield rates and faradaic efficiency (FE), 3,[14][15][16] falling short of the industrial standard for NH 3 production. 17,18 These obstacles arise due to the exceptionally high decomposition energy of the triple bond in N 2 (941 kJ mol −1 ) and the limited solubility of N 2 in water.…”