Author(s)

Yulong Cao ¹

Affiliation(s)

¹ Xihua University, Chengdu, Sichuan, 610039, China

Corresponding Author

Yulong Cao

ABSTRACT

The electrochemical nitrogen reduction reaction (eNRR) for ammonia synthesis under ambient conditions presents a promising alternative to the energy-intensive Haber-Bosch process. Single-atom catalysts (SACs) have emerged as highly efficient platforms for eNRR due to their maximal atom utilization, unique electronic structures, and well-defined active sites. The central challenge lies in precisely regulating the coordination environment of the metal centers to optimize their catalytic performance and steer the reaction pathways towards high ammonia yield and Faradaic efficiency. This study systematically investigates the influence of coordination structures, including coordination number, identity of coordinating atoms (e.g., N, O, S, P), and the local carbon matrix defects, on the eNRR activity and selectivity of M-N-C type SACs (M = Fe, Mo, Ru). Through a combination of tailored synthesis, advanced characterization, and electrochemical evaluation, we demonstrate that a lowered symmetric coordination number and the incorporation of heteroatoms (e.g., S) adjacent to the metal center can significantly modulate the electron density of the active site. This electronic modulation weakens the competitive hydrogen evolution reaction (HER) and promotes the activation and protonation of N2 via an alternating pathway. The optimized Mo-S1N3 catalyst exhibits an exceptional ammonia yield rate of 62.1 μg h⁻¹ mgcat⁻¹ and a Faradaic efficiency of 35.6% at -0.3 V versus the reversible hydrogen electrode (RHE) in 0.1 M Na2SO4. This work elucidates the fundamental structure-activity relationships, providing a strategic guideline for the rational design of high-performance SACs for sustainable ammonia production.

KEYWORDS

Electrocatalytic nitrogen reduction; Ammonia synthesis; Single-atom catalysts; Coordination environment; Molybdenum-based catalysts; Electronic structure modulation; Reaction pathway; Hydrogen evolution suppression

CITE THIS PAPER

Yulong Cao. Research on the regulation of coordination environment and reaction pathways of single-atom catalysts in electrocatalytic nitrogen reduction for ammonia synthesis. Journal of Materials, Processing and Design (2026). Vol. 10, No.1, 11-18. DOI: http://dx.doi.org/10.23977/jmpd.2026.100102.

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