dc.contributor.author | Buan, Marthe Emelie Melandsø | |
dc.contributor.author | Cognigni, Andrea | |
dc.contributor.author | Walmsley, John | |
dc.contributor.author | Muthuswamy, Navaneethan | |
dc.contributor.author | Rønning, Magnus | |
dc.date.accessioned | 2020-11-25T08:50:21Z | |
dc.date.available | 2020-11-25T08:50:21Z | |
dc.date.created | 2019-04-30T14:22:47Z | |
dc.date.issued | 2019 | |
dc.identifier.citation | Catalysis Today. 2019, 1-11. | en_US |
dc.identifier.issn | 0920-5861 | |
dc.identifier.uri | https://hdl.handle.net/11250/2689470 | |
dc.description.abstract | Understanding the role of iron and the nature of the active sites in nitrogen-doped carbon nanomaterials is vital for their future application as oxygen reduction electrocatalysts in fuel cells. In this paper, porphyrin-like Fe-N4 sites have been identified in nitrogen-doped carbon nanofibers (N-CNFs) grown from iron nanoparticles by chemical vapor deposition (CVD). Acid treatment of the N-CNFs removed the iron growth particles and about 50% of the nitrogen groups from the pristine N-CNFs, without affecting the oxygen reduction performance. Performing electron energy loss spectroscopy (EELS) on the acid treated and annealed N-CNFs confirmed that the CVD synthesis method leads to iron being atomically incorporated into the N-CNF structure. Furthermore, X-ray absorption near-edge structure (XANES) analysis of the Fe K-edge indicates that the iron atoms are stabilized by four nitrogen atoms, reminiscent of the Fe-N4 structure found in porphyrins. An evolution of the XANES spectrum was observed when performing the measurements under mildly reducing conditions, which was explained by oxygen being adsorbed on the Fe-N4 sites at room temperature. The Fe-N4 moieties embedded in the N-CNFs were resistant to acid leaching and the results suggest that these Fe-N4 sites are active sites for the oxygen reduction in N-CNFs. | en_US |
dc.language.iso | eng | en_US |
dc.publisher | Elsevier | en_US |
dc.rights | Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal | * |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/deed.no | * |
dc.subject | Expanded graphite | en_US |
dc.subject | Chemical vapor deposition | en_US |
dc.subject | Carbon nanofiber | en_US |
dc.subject | Nitrogen-doped | en_US |
dc.subject | Oxygen reduction | en_US |
dc.title | Active sites for the oxygen reduction reaction in nitrogen-doped carbon nanofibers | en_US |
dc.type | Peer reviewed | en_US |
dc.type | Journal article | en_US |
dc.description.version | publishedVersion | en_US |
dc.rights.holder | © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). | en_US |
dc.source.pagenumber | 248-258 | en_US |
dc.source.volume | 357 | en_US |
dc.source.journal | Catalysis Today | en_US |
dc.identifier.doi | 10.1016/j.cattod.2019.01.018 | |
dc.identifier.cristin | 1694798 | |
dc.relation.project | Norges forskningsråd: 197405 | en_US |
dc.relation.project | Norges forskningsråd: 218406 | en_US |
dc.relation.project | EC/FP7/280658 | en_US |
cristin.unitcode | 7401,80,64,0 | |
cristin.unitname | Materialer og nanoteknologi | |
cristin.ispublished | true | |
cristin.fulltext | postprint | |
cristin.qualitycode | 2 | |