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Oxygen evolution and reduction on Fe-doped NiOOH: influence of solvent, dopant position and reaction mechanism

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Show simple item record Vandichel, Matthias Laasonen, Kari Kondov, Ivan 2020-08-05T11:43:40Z 2020
dc.description peer-reviewed en_US
dc.description.abstract The oxygen evolution reaction (OER) is the limiting factor in an electrolyzer and the oxygen reduction reaction (ORR) the limiting factor in a fuel cell. In OER, water is converted to O2 and H+/e- pairs, while in ORR the reverse process happens to form water. Both reactions and their efficiency are important enablers of a hydrogen economy where hydrogen will act as a fuel or energy storage medium. OER and ORR can both be described assuming a 4-step electrochemical mechanism with coupled H+/e- transfers between 4 intermediates (M-*, M-OH, M=O, M-OOH, M = active site). Previously, it was shown that an unstable M-OOH species can equilibrate to an MOO species and a hydrogenated acceptor site (M-OOH/eq), enabling a bifunctional mechanism. Within OER, the presence of Fe within an NiOOH acceptor site was found to be beneficial to lower the required overpotential (Vandichel et al. Chemcatchem, 2020, 12 (5), 1436-1442). In this work, we present the first proof-of-concept study of various possible mechanisms (standard and bifunctional ones) for OER and ORR, i.e. we include now the active edge sites and hydrogen acceptor sites in the same model system. Furthermore, we consider water as solvent to describe the equilibration of the M-OOH species to M-OOH/eq, a crucial step that enables a bifunctional route to be operative. Additionally, different single Fe-dopant positions in an exfoliated NiOOH model are considered and four different reaction schemes are studied for OER and the reverse ORR process. The results are relevant in alkaline conditions, where the studied model systems are stable. Certain Fe-dopant positions result in active Ni-edge sites with very low overpotentials provided water is present within the model system. en_US
dc.language.iso eng en_US
dc.publisher Springer en_US
dc.relation.ispartofseries Topics in Catalysis; 63, pp. 833-845
dc.rights The original publication is available at en_US
dc.subject mixed metal-oxy-hydroxides en_US
dc.subject oxygen evolution reaction(s) (OER) en_US
dc.subject oxygen reduction reaction(s) (ORR) en_US
dc.subject bifunctional route en_US
dc.subject universal scaling relations en_US
dc.title Oxygen evolution and reduction on Fe-doped NiOOH: influence of solvent, dopant position and reaction mechanism en_US
dc.type info:eu-repo/semantics/article en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.identifier.doi 10.1007/s11244-020-01334-8
dc.contributor.sponsor Ministry of Science, Research and the Arts Baden-Württemberg en_US
dc.contributor.sponsor Federal Ministry of Education and Research en_US 2021-07-29
dc.embargo.terms 2021-07-29 en_US
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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