Structure Sensitivity of Methanol Electrooxidation on Transition Metals.
We have investigated the structure sensitivity of methanol electrooxidation on eight transition metals (Au, Ag, Cu, Pt, Pd, Ir, Rh, and Ni) using periodic, self-consistent density functional theory (DFT- GGA). Using the adsorption energies of 16 intermediates on two different facets of these eight f...
| Publicado en: | Journal of the American Chemical Society Vol. 131; no. 40; pp. 14381 - 14390 |
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| Autores principales: | , |
| Formato: | Artículo |
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American Chemical Society
10/14/2009
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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=44750078&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 44750078 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: 10/14/2009 vid: 131 iid: 40 pid: 997 pub: American Chemical Society artinfo: ui: 44750078 10.1021/ja904010u ppf: 14381 ppct: 9 formats: tig: atl: Structure Sensitivity of Methanol Electrooxidation on Transition Metals. aug: au: Ferrin, Peter Mavrikakis, Manos affil: Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 su: Transition metals Methanol Electrolytic oxidation Density functionals Metallurgy Electrochemical analysis sug: subj: Transition metals Methanol Electrolytic oxidation Density functionals Metallurgy Electrochemical analysis ab: We have investigated the structure sensitivity of methanol electrooxidation on eight transition metals (Au, Ag, Cu, Pt, Pd, Ir, Rh, and Ni) using periodic, self-consistent density functional theory (DFT- GGA). Using the adsorption energies of 16 intermediates on two different facets of these eight face-centered- cubic transition metals, combined with a simple electrochemical model, we address the differences in the reaction mechanism between the (111) and (100) facets of these metals. We investigate two separate mechanisms for methanol electrooxidation: one going through a CO* intermediate (the indirect pathway) and another that oxidizes methanol directly to CO without CO* as an intermediate (the direct pathway). A comparison of our results for the (111) and (100) surfaces explains the origin of methanol electrooxidation's experimentally-established structure sensitivity on Pt surfaces. For most metals studied, on both the (111) and (100) facets, we predict that the indirect mechanism has a higher onset potential than the direct mechanism. Ni(111), Au(100), and Au(111) are the cases where the direct and indirect mechanisms have the same onset potential. For the direct mechanism, Rh, Ir, and Ni show a lower onset potential on the (111) facet, whereas Pt, Cu, Ag, and Au possess lower onset potential on the (100) facet. Pd(100) and Pd(111) have the same onset potential for the direct mechanism. These results can be rationalized by the stronger binding energy of adsorbates on the (100) facet versus the (111) facet. Using linear scaling relations, we establish reactivity descriptors for the (100) surface similar to those recently developed for the (111) surface; the free energies of adsorbed CO* and OH* can describe methanol electrooxidation trends on various metal surfaces reasonably well. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2009 holdings: @attributes: islocal: N |
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