Impacts of Imidazolate Ligand on Performance of Zeolitic-Imidazolate Framework-Derived Oxygen Reduction Catalysts
- Argonne National Lab. (ANL), Lemont, IL (United States); Beijing Univ. of Technology (China)
- Argonne National Lab. (ANL), Lemont, IL (United States)
- Argonne National Lab. (ANL), Lemont, IL (United States); Northern Illinois Univ., DeKalb, IL (United States)
- National Univ. of Singapore (Singapore)
- Beijing Univ. of Technology (China)
Carbon-hosted Fe-N-coordinated (Fe/N/C) materials, especially those derived from thermolysis of iron-added zinc-based zeoliteimidazolate frameworks (ZIFs), have emerged as the most promising platinum group metal-free (PGM-free) oxygen reduction reaction (ORR) catalysts. However, the impacts of the precursory ZIF structure and their conversion chemistry during thermal activation to the final catalytic activity remain to be further explored in the process of continuously refining the catalyst performance. In this work, we synthesized a series of Fe-doped ZIFs with different imidazolate ligands and systematically studied the correlation between the crystal structures with the final ORR catalytic activity in an alkaline electrolyte. We also investigated the ZIF decomposition chemistry during pyrolysis using a thermogravimetric mass-spectroscopic analysis. We demonstrated that imidazole side-chain substitution alters the ZIF's decomposition during pyrolysis, influencing the elemental compositions, surface properties, graphitization levels, and ultimately the catalytic performance. The Zn(mIm)2TPIBP catalyst affords the highest ORR activity with a half-wave potential of 0.93 V vs RHE, representing the best among all PGM-free catalysts studied.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States). Center for Nanoscale Materials (CNM)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Fuel Cell Technologies Office; USDOE Office of Science (SC)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1574899
- Journal Information:
- ACS Energy Letters, Journal Name: ACS Energy Letters Journal Issue: 10 Vol. 4; ISSN 2380-8195
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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