Relevant Properties of Carbon Support Materials in Successful Fe-N-C Synthesis for the Oxygen Reduction Reaction: Study of Carbon Blacks and Biomass-Based Carbons

• Published in: Materials Vol. 14; no. 1; p. 45
• Main Authors: Hülstede, Julia, Schonvogel, Dana, Schmies, Henrike, Wagner, Peter, Schröter, Frank, Dyck, Alexander, Wark, Michael
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24-12-2020; MDPI
• Subjects: Acids; activated biomass; Activated carbon; Biomass; Carbon; Carbon nanotubes; carbon support; Catalysts; Electrodes; Electrolytes; Fe-N-C materials; Fuel cells; Iron; Iron carbides; Nanoparticles; Nitrogen; nonprecious metal catalysts; oxygen reduction reaction; Oxygen reduction reactions; Phosphoric acid; porous carbon; Properties (attributes); Stainless steel; Sustainable development; Sustainable materials; United States > US; Germany; porous carbon; Fe-N-C materials; nonprecious metal catalysts; oxygen reduction reaction; activated biomass; carbon support
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma14010045

Fe-N-C materials are promising non-precious metal catalysts for the oxygen reduction reaction in fuel cells and batteries. However, during the synthesis of these materials less active Fe-containing nanoparticles are formed in many cases which lead to a decrease in electrochemical activity and stability. In this study, we reveal the significant properties of the carbon support required for the successful incorporation of Fe-N-related active sites. The impact of two carbon blacks and two activated biomass-based carbons on the Fe-N-C synthesis is investigated and crucial support properties are identified. Carbon supports having low portions of amorphous carbon, moderate surface areas (>800 m
/g) and mesopores result in the successful incorporation of Fe and N on an atomic level and improved oxygen reduction reaction (ORR) activity. A low surface area and especially amorphous parts of the carbon promote the formation of metallic iron species covered by a graphitic layer. In contrast, highly microporous systems with amorphous carbon provoke the formation of less active iron carbides and carbon nanotubes. Overall, a phosphoric acid activated biomass is revealed as novel and sustainable carbon support for the formation of Fe-N
sites. Overall, this study provides valuable and significant information for the future development of novel and sustainable carbon supports for Fe-N-C catalysts.