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dc.contributor.authorBlakemore, James D.
dc.contributor.authorSchley, Nathan D.
dc.contributor.authorKushner-Lenhoff, Maxwell N.
dc.contributor.authorWinter, Andrew M.
dc.contributor.authorD'Souza, Francis
dc.contributor.authorCrabtree, Robert H.
dc.contributor.authorBrudvig, Gary W.
dc.identifier.citationJames D. Blakemore, Nathan D. Schley, Maxwell N. Kushner-Lenhoff, Andrew M. Winter, Francis D’Souza, Robert H. Crabtree, and Gary W. Brudvig. 2012. Comparison of amorphous iridium water-oxidation electrocatalysts prepared from soluble precursors. Inorganic Chemistry, v.51 (14), 7749-7763.
dc.descriptionClick on the DOI link below to access the article (may not be free).en_US
dc.description.abstractElectrodeposition of iridium oxide layers from soluble precursors provides a route to active thin-layer electrocatalysts for use on water-oxidizing anodes. Certain organometallic half-sandwich aqua complexes of iridium form stable and highly active oxide films upon electrochemical oxidation in aqueous solution. The catalyst films appear as blue layers on the anode when sufficiently thick, and most closely resemble hydrous iridium(III,IV) oxide by voltammetry. The deposition rate and cyclic voltammetric response of the electrodeposited material depend on whether the precursor complex contains a pentamethylcyclopentadieneyl (Cp*) or cyclopentadienyl ligand (Cp), and do not match, in either case, iridium oxide anodes prepared from non-organometallic precursors. Here, we survey our organometallic precursors, iridium hydroxide, and pre-formed iridium oxide nanoparticles. From electrochemical quartz crystal nanobalance (EQCN) studies, we find differences in the rate of electrodeposition of catalyst layers from the two half-sandwich precursors; however, the resulting layers operate as water-oxidizing anodes with indistinguishable overpotentials and HID isotope effects. Furthermore, using the mass data collected by EQCN and not otherwise available, we show that the electrodeposited materials are excellent catalysts for the water-oxidation reaction, showing maximum turnover frequencies greater than 0.5 mol O-2 (mol iridium)(-1) s(-1) and quantitative conversion of current to product dioxygen. Importantly, these anodes maintain their high activity and robustness at very low iridium loadings. Our organometallic precursors contrast with pre-formed iridium oxide nanoparticles, which form an unstable electrodeposited material that is not stably adherent to the anode surface at even moderately oxidizing potentials.en_US
dc.publisherAmerican Chemical Societyen_US
dc.relation.ispartofseriesInorganic Chemistry; v.51 no.14
dc.subjectOxide Thin-Filmsen_US
dc.subjectOxygen evolutionen_US
dc.subjectArtificial photosynthesisen_US
dc.titleComparison of amorphous iridium water-oxidation electrocatalysts prepared from soluble precursorsen_US
dc.description.versionPeer reviewed
dc.rights.holderCopyright © 2012 American Chemical Society

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