Converting carbon black into an efficient and multi-site ORR electrocatalyst: the importance of bottom-up construction parameters

• Type: Article in International Scientific Journal
• Date: 2023-11

Authors

Rui S. Ribeiro (Author) FEUP; Marc Florent (Author) Other; Juan J. Delgado (Author) Other; M. Fernando R. Pereira (Author) FEUP; Teresa J. Bandosz (Author) Other

Journal

Title: Nanoscale

Vol. 15

Pages: 18592-18602

ISSN: 2040-3364

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 0 Citations

Associated Projects

BiCat4Energy - Electrocatalisadores bifuncionais baseados em materiais de carbono isentos de metais nobres para a produção de energia renovável: melhoramento da tecnologia da Célula de Combustível Unitária Regenerativa.

LA LSRE-LCM - Financiamento Plurianual 2020-2023 para a Unidade LA LSRE-LCM Laboratório de Processos de Separação e Reacção - Laboratório de Catálise e Materiais

Other information

Authenticus ID: P-00Z-CGW

DOI: 10.1039/d3nr04244h

Abstract (EN): To boost efficient energy transitions, alternatives to expensive and unsustainable noble metal-based electrocatalysts for the oxygen reduction reaction (ORR) are needed. Having this in mind, carbon black - Black Pearls 2000 (BP) was enriched in active nitrogen-containing centers, including single-atom Fe-N sites surrounded by Fe nanoclusters, through a synthesis methodology employing only broadly available precursors. The methodical approach taken to optimize the synthesis conditions highlighted the importance of (1) a proper choice of the Fe precursor; (2) melamine as an N source to limit the formation of magnetite crystals and modulate the charge density nearby the active sites, and glucose to chelate/isolate Fe atoms and thus allow the Fe-N coordination to be established, with a limiting formation of Fe0 clusters; and (3) a careful dosing of the Fe load. The ORR on the optimized electrocatalyst (Fe0.06-N@BP) proceeds mostly through a four-electron pathway, having an onset potential (0.912 V vs. RHE) and limiting current density (4.757 mA cm-2) above those measured on Pt/C (0.882 V and 4.657 mA cm-2, respectively). Moreover, the current density yielded by Fe0.06-N@BP after 24 h at 0.4 V vs. RHE was still above that of Pt/C at t = 0 (4.44 mA cm-2), making it a promising alternative to noble metal-containing electrocatalysts in fuel cells. Surface modification of highly porous and conductive carbon black was performed. Preserved porosity, single-atom Fe-N centers, Fe nanoclusters, and other N-containing sites contribute to high electrocatalytic activity and stability towards the ORR.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11