• Journal of Inorganic Materials
  • Vol. 39, Issue 5, 561 (2024)
Honglan LI1, Junmiao ZHANG1, Erhong SONG2,*, and Xinglin YANG1,*
Author Affiliations
  • 11. School of Energy and Power Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
  • 22. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
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    DOI: 10.15541/jim20230433 Cite this Article
    Honglan LI, Junmiao ZHANG, Erhong SONG, Xinglin YANG. Mo/S Co-doped Graphene for Ammonia Synthesis: a Density Functional Theory Study[J]. Journal of Inorganic Materials, 2024, 39(5): 561 Copy Citation Text show less

    Abstract

    In the industrial landscape, the well-established Haber-Bosch method is employed for the catalytic synthesis of ammonia (NH3) from hydrogen and nitrogen gases, necessitating elevated temperatures (400-600 ℃) and high pressures (150-300 atm, 1 atm= 0.101325 MPa). In response to the imperative to reduce energy consumption and environment impact imposed by this synthetic process, significant research efforts have converged on realizing NH3 synthesis under ambient conditions. This study delves into the realm of N2 electrocatalytic reduction to NH3, using density functional theory (DFT) calculations to explore the feasibility of employing graphene co-doped with a combination of transition metal elements (e.g., Fe, Nb, Mo, W, and Ru) and non-metal elements (e.g., B, P, and S) as catalyst for ammonia synthesis. The findings underscore that Mo and S co-doped graphene (Mo/S graphene) demonstrates an exceptionally low electrode potential of 0.47 V for NH3 synthesis, with the key rate-controlling step centered around the formation of the intermediate *NNH. Especially, the ammonia synthesis potential is found to be lower than the hydrogen evolution potential (0.51 V), conclusively affirming the selectivity of nitrogen reduction to ammonia. Furthermore, through ab initio molecular dynamics calculations, the study attests to the remarkable thermodynamic stability of the Mo/S co-doped graphene system under room temperature conditions. Notably, electronic structure analysis validates that the ability of electron communication of the transition metal plays a pivotal role in dictating the efficiency of N2 electrocatalytic reduction. It can be tactically optimized through controlled modulation of the influence of the non-metal element on the coordination environment of the transition metal, thus substantially enhancing catalytic performance.
    Eads = EsystemEcatalystEm

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    Eb = EcatalystEXGETM

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    ΔG = ΔE + ΔEZPETΔS + ΔGU + ΔGpH

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    UL = ΔGPDS/e

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    Honglan LI, Junmiao ZHANG, Erhong SONG, Xinglin YANG. Mo/S Co-doped Graphene for Ammonia Synthesis: a Density Functional Theory Study[J]. Journal of Inorganic Materials, 2024, 39(5): 561
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