Abstract
AbstractIn pursuing cheap and effective oxygen reduction catalysts, the Fe/N/C system emerges as a promising candidate. Nevertheless, the structural transformations of starting materials into Fe- and N-doped carbon catalysts remains poorly characterized under pyrolytic conditions. Here, we explore the evolution of Fe species and track the formation of Fe–N4 site development by employing diverse in-situ diagnostic techniques. In-situ heating microscopy reveals the initial formation of FeOx nanoparticles and subsequent internal migration within the carbon matrix, which stops once FeOx is fully reduced. The migration and decomposition of nanoparticles then leads to carbon layer reconstruction. Experimental and theoretical analysis reveals size-dependent behavior of FeOx where nanoparticles below 7 nm readily release Fe atoms to form Fe–N4 while nanoparticles with sizes >10 nm tend to coalesce and impede Fe–N4 site formation. The work visualizes the pyrolysis process of Fe/N/C materials, providing theoretical guidance for the rational design of catalysts.
Publisher
Springer Science and Business Media LLC
Reference43 articles.
1. Chong, L. et al. Ultralow-loading platinum-cobalt fuel cell catalysts derived from imidazolate frameworks. Science 362, 1276–1281 (2018).
2. Yang, C. et al. Sulfur-anchoring synthesis of platinum intermetallic nanoparticle catalysts for fuel cells. Science 374, 459–464 (2021).
3. Zhang, T. et al. Adjusting the alloying degree of Pt3Zn to improve acid oxygen reduction activity and stability. J. Electrochem 28, 2106091 (2022).
4. Huang, L. et al. Progress of Pt-based catalysts in proton-exchange membrane fuel cells: A review. J. Electrochem 28, 2108061 (2022).
5. Shao, M. et al. Recent advances in electrocatalysts for oxygen reduction reaction. Chem. Rev. 116, 3594–3657 (2016).
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