Electrochemical Detection of Transient Cobalt Hydride Intermediates of Electrocatalytic Hydrogen Production.
A large variety of molecular cobalt complexes are used as electrocatalysts for H2 production, but the key cobalt hydride intermediates are frequently difficult to detect and characterize due to their high reactivity. We report that a combination of variable scan rate cyclic voltammetry and foot-of-t...
| Publicado en: | Journal of the American Chemical Society Vol. 138; no. 26; pp. 8309 - 8319 |
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| Autores principales: | , |
| Formato: | Artículo |
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American Chemical Society
7/6/2016
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=116961639&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 116961639 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 7/6/2016 vid: 138 iid: 26 pid: 997 pub: American Chemical Society artinfo: ui: 116961639 10.1021/jacs.6b04779 ppf: 8309 ppct: 10 formats: tig: atl: Electrochemical Detection of Transient Cobalt Hydride Intermediates of Electrocatalytic Hydrogen Production. aug: au: Wiedner, Eric S. Bullock, R. Morris affil: Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, P.O. Box 999, K2-57, Richland, Washington 99352, United States su: Cobalt Electrocatalysts Cobalt hydrides Cyclic voltammetry Density functional theory sug: subj: Cobalt Electrocatalysts Cobalt hydrides Cyclic voltammetry Density functional theory ab: A large variety of molecular cobalt complexes are used as electrocatalysts for H2 production, but the key cobalt hydride intermediates are frequently difficult to detect and characterize due to their high reactivity. We report that a combination of variable scan rate cyclic voltammetry and foot-of-the-wave analysis (FOWA) can be used to detect transient CoH and CoH intermediates of electrocatalytic H2 production by [Co(PN)(CHCN)] and Co(dmgBF) (CHCN). In both cases, reduction of a transient catalytic intermediate occurs at a potential that coincides with the Co/I couple. Each reduction displays quasireversible electron-transfer kinetics, consistent with reduction of a CoH intermediate to CoH, which is then protonated by acid to generate H2. A bridge-protonated Co species was ruled out as a catalytic intermediate for Co(dmgBF) (CHCN) from voltammograms recorded at 1000 psi of H. Density functional theory was used to calculate Co-H and Co-H bond strengths for both catalysts. Despite having very different ligands, the cobalt hydrides of both catalysts possess nearly identical heterolytic and homolytic Co-H bond strengths for the CoH and CoH intermediates. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2016 holdings: @attributes: islocal: N |
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