Enhanced ammonia yield rate from nitrogen on collapsed dodecahedral-shaped Co/NC electrocatalyst

• Published in: Electrochimica acta Vol. 508; p. 145278
• Main Authors: Wei, Bohui, Liang, Yaodong, Li, Yuangang, Yang, Xudong, Yao, Chenzhong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.12.2024
• Subjects: Defective engineering; Electrocatalysis; Nitrogen reduction reaction; Porous carbon; Yield rate of ammonia; Electrocatalysis; Yield rate of ammonia; Porous carbon; Nitrogen reduction reaction; Defective engineering
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2024.145278

•Co/NC catalysts with a collapsed dodecahedral morphology could be prepared by pyrolysis of ZIF-67.•High surface area and abundant defects of Co/NC can be controlled by tuning pyrolysis temperature.•The yield rates of NH3 can reach up to 60.57 μg h-1 mgcat.−1 at −0.1 v (vs RHE) .•Co/NC catalyst has great stability and reusability.•The enhanced E-NRR activity of Co/NC may be originated mainly from an associative distal pathway on the Co-N3C sites and the defects of C in alkaline electrolyte. Nowadays, multi-component non-precious metal catalysts have been considered as a significant strategy for enhancing the yield of synthesizing NH3 by electrocatalytic nitrogen reduction reaction (E-NRR). In the present work, carbon composites doped with well-dispersed Co and N (Co/NC) were prepared by pyrolyzing zeolitic imidazolate framework-67 (ZIF-67) at various temperatures protected under a N2 flow. Co/NC exhibits a collapsed dodecahedral morphology with a mesoporous structure (3.5–4 nm). The chemical states of Co/N and the structural defects of C are closely related to the carbonization temperature. In a N2-saturated 0.1 M KOH electrolyte, the as-prepared catalysts exhibit an NH3 yield rate (Y(NH3)) of 60.57 μg h-1 mgcat.-1 and a Faradaic efficiency (FE) of 23.3 % at -0.1 V (vs the reversible hydrogen electrode, RHE) at ambient conditions. The enhanced E-NRR activity of Co/NC may primarily originate from an associative distal pathway on the Co-N3C sites and the carbon defects in an alkaline electrolyte. Specifically, this work presents a three-component E-NRR catalyst with excellent stability and great activity based on Co/NC. [Display omitted]