Exploring stable non-precious catalysts with excellent activities for electrochemical oxygen reduction is vital for minimizing noble metal consumption in the study of sustainable energy technologies.
Single-atom Fe homogenously anchored on N-doped carbon (Fe-Nx/C) catalysts are considered as the most promising candidate. However, environmentally hazardous and toxic solvents as well as acid are necessarily needed in the synthesis of Fe-Nx/C catalysts, restricting the application on a large scale.
"Considering the overall factors of practical application, we must propose a green synthesis method for highly efficient catalysts," said Prof. LIANG Hanpu from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences (CAS).
Recently, a research team led by Prof. LIANG reported the facile and environment-friendly synthesis of a single-atom Fe catalyst. Their study was published in ACS Sustainable Chemistry & Engineering.
The researchers synthesized iron doped ZIF8 precursor in aqueous solution, which was followed by one-step high temperature pyrolysis without the need for subsequent acid leaching. Then, they obtained rod-like nitrogen doped carbon nanorods decorated with isolated Fe-N4 sites (Fe-SA/NCS).
The as-synthesized Fe-SA/NCS catalyst exhibited remarkable electrocatalytic performance and long-term stability for oxygen reduction reaction both in KOH and HClO4, which was attributed to Fe-N4 active sites.
Moreover, the Zinc-Air battery with Fe-SA/NCS as cathode material exhibited a relatively low charge/discharge overpotential, higher power density as well as long-term rechargeable stability compared to commercial JM Pt/C catalyst.
The synthetic strategy developed in this study affords an efficient approach for the green synthesis of non-precious single-atom catalysts for high-performance fuel cells and metal-air batteries.
(a) Schematic illustration for the synthetic procedure; (b)-(i) electron microscopy characterization of Fe-SA/NCS (Image by YANG Chen)
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