Resolving the Dilemma of Fe-N-C Catalysts by the Selective Synthesis of Tetrapyrrolic Active Sites via an Imprinting Strategy.

Autor:	Menga D; Chair of Technical Electrochemistry, Department of Chemistry and Catalysis Research Center, Technische Universität München (TUM), Lichtenbergstraße 4, 85748 Garching, Germany., Low JL; Chair for Theoretical Chemistry, Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany., Li YS; Chair of Technical Electrochemistry, Department of Chemistry and Catalysis Research Center, Technische Universität München (TUM), Lichtenbergstraße 4, 85748 Garching, Germany., Arčon I; Laboratory of Quantum Optics, University of Nova Gorica, SI-5001 Nova Gorica, Slovenia.; Department of Low and Medium Energy Physics, Jožef Stefan Institute, Jamova 39, SI-1001 Ljubljana, Slovenia., Koyutürk B; Chair of Technical Electrochemistry, Department of Chemistry and Catalysis Research Center, Technische Universität München (TUM), Lichtenbergstraße 4, 85748 Garching, Germany., Wagner F; Department of Physics, Technische Universität München (TUM), James-Franck-Straße 1, 85748 Garching, Germany., Ruiz-Zepeda F; Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 10, SI-1000 Ljubljana, Slovenia., Gaberšček M; Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 10, SI-1000 Ljubljana, Slovenia., Paulus B; Chair for Theoretical Chemistry, Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany., Fellinger TP; Chair of Technical Electrochemistry, Department of Chemistry and Catalysis Research Center, Technische Universität München (TUM), Lichtenbergstraße 4, 85748 Garching, Germany.; Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 44-46, 12203 Berlin, Germany.
Jazyk:	angličtina
Zdroj:	Journal of the American Chemical Society [J Am Chem Soc] 2021 Nov 03; Vol. 143 (43), pp. 18010-18019. Date of Electronic Publication: 2021 Oct 24.
DOI:	10.1021/jacs.1c04884
Abstrakt:	Combining the abundance and inexpensiveness of their constituent elements with their atomic dispersion, atomically dispersed Fe-N-C catalysts represent the most promising alternative to precious-metal-based materials in proton exchange membrane (PEM) fuel cells. Due to the high temperatures involved in their synthesis and the sensitivity of Fe ions toward carbothermal reduction, current synthetic methods are intrinsically limited in type and amount of the desired, catalytically active Fe-N 4 sites, and high active site densities have been out of reach (dilemma of Fe-N-C catalysts). We herein identify a paradigm change in the synthesis of Fe-N-C catalysts arising from the developments of other M-N-C single-atom catalysts. Supported by DFT calculations we propose fundamental principles for the synthesis of M-N-C materials. We further exploit the proposed principles in a novel synthetic strategy to surpass the dilemma of Fe-N-C catalysts. The selective formation of tetrapyrrolic Zn-N 4 sites in a tailor-made Zn-N-C material is utilized as an active-site imprint for the preparation of a corresponding Fe-N-C catalyst. By successive low- and high-temperature ion exchange reactions, we obtain a phase-pure Fe-N-C catalyst, with a high loading of atomically dispersed Fe (>3 wt %). Moreover, the catalyst is entirely composed of tetrapyrrolic Fe-N 4 sites. The density of tetrapyrrolic Fe-N 4 sites is more than six times as high as for previously reported tetrapyrrolic single-site Fe-N-C fuel cell catalysts.
Databáze:	MEDLINE
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