Electrocatalytic Water Oxidation with α-[Fe(mcp)(OTf)2] and Analogues
dc.contributor.author
dc.date.accessioned
2021-02-23T08:00:31Z
dc.date.available
2021-02-23T08:00:31Z
dc.date.issued
2021-02-11
dc.identifier.issn
2155-5435
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dc.description.abstract
The complex α-[Fe(mcp)(OTf)2] (mcp = N,N′-dimethyl-N,N′-bis(pyridin-2-ylmethyl)-cyclohexane-1,2-diamine and OTf = trifluoromethanesulfonate anion) was reported in 2011 by some of us as an active water oxidation (WO) catalyst in the presence of sacrificial oxidants. However, because chemical oxidants are likely to take part in the reaction mechanism, mechanistic electrochemical studies are critical in establishing to what extent previous studies with sacrificial reagents have actually been meaningful. In this study, the complex α-[Fe(mcp)(OTf)2] and its analogues were investigated electrochemically under both acidic and neutral conditions. All the systems under investigation proved to be electrochemically active toward the WO reaction, with no major differences in activity despite the structural changes. Our findings show that WO-catalyzed by mcp–iron complexes proceeds via homogeneous species, whereas the analogous manganese complex forms a heterogeneous deposit on the electrode surface. Mechanistic studies show that the reaction proceeds with a different rate-determining step (rds) than what was previously proposed in the presence of chemical oxidants. Moreover, the different kinetic isotope effect (KIE) values obtained electrochemically at pH 7 (KIE ∼ 10) and at pH 1 (KIE = 1) show that the reaction conditions have a remarkable effect on the rds and on the mechanism. We suggest a proton-coupled electron transfer (PCET) as the rds under neutral conditions, whereas at pH 1 the rds is most likely an electron transfer (ET)
dc.description.sponsorship
NWO Echo grant 717.014.008. PGC2018-101737-B-I00 and
2017 SGR 00264 grants
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application/pdf
dc.language.iso
eng
dc.publisher
American Chemical Society (ACS)
dc.relation
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-101737-B-I00/ES/CATALISIS DE OXIDACION BIOINSPIRADA MEDIANTE DISEÑO RACIONAL DE CATALIZADORES/
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Reproducció digital del document publicat a: https://doi.org/10.1021/acscatal.0c05439
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ACS Catalysis, 2021, vol. 11, p. 2583–2595
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Articles publicats (D-Q)
dc.rights
Attribution-NonCommercial-NoDerivatives 4.0 International
dc.rights.uri
dc.title
Electrocatalytic Water Oxidation with α-[Fe(mcp)(OTf)2] and Analogues
dc.type
info:eu-repo/semantics/article
dc.rights.accessRights
info:eu-repo/semantics/openAccess
dc.type.version
info:eu-repo/semantics/publishedVersion
dc.identifier.doi
dc.identifier.idgrec
032776
dc.contributor.funder
dc.type.peerreviewed
peer-reviewed
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