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AuthorHartmann, Heinrichdc.contributor.author
Date of accession2016-03-15T09:05:10Zdc.date.accessioned
Available in OPARU since2016-03-15T09:05:10Zdc.date.available
Year of creation2013dc.date.created
AbstractIn this thesis the adsorption of CO and deuterium on Pt/Ru(0001) monolayer films and on PdRu/Ru(0001) surface alloys was investigated with TPD and IRAS, additionally the coadsorption of both molecules was investigated on the Pt/Ru(0001) surface under UHV conditions. The Pd and Pt parts of the surface displayed significantly lower adsorption energies for both probe molecules, compared to the Pd(111) and Pt(111) surfaces. This was explained by strain and electronic effects resulting from the formation of the bimetallic surfaces. For CO adsorbed on Pt/Ru(0001) the increase in mobility which results from annealing the surface from 90 to 150 K leads to spill-over of CO from the Pt to the Ru parts of the surface. This results in CO coverages on the Ru parts of the surface which are considerably higher than found on Ru(0001). In the case of CO and deuterium coadsorption, the preadsorption of one species was observed to block the subsequent adsorption of the respective other species. However, while no D2 adsorption was possible on surfaces saturated with CO, limited CO adsorption was still possible on surfaces covered with D2. Increasing Pt coverages were found to lead to an increase in COad coverages which can be achieved on bimetallic surfaces precovered with Dad. The combined results of adsorption experiments on the PdRu/Ru(0001) and Pt/Ru(0001) surfaces show that while the adsorption of both D2 and CO is weakened compared to the pure metallic surface components, the effect is more pronounced for D2 than for CO. For D2 the combination of two metals has a negative impact on the maximum coverage as well as on the adsorption kinetics. Most likely this is caused by an activation barrier for D2 adsorption on the weaker binding part of the surface. In the case of CO and D2 coadsorption on Pt/Ru(0001), the interactions between the two adsorbates lead to an additional destabilization of Dad, causing increasing displacement/blocking of Dad by CO with increasing Pt coverage.dc.description.abstract
Languageendc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandarddc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v3dc.rights.uri
KeywordBimetallic surfacedc.subject
KeywordCOdc.subject
KeywordIRASdc.subject
KeywordPdRudc.subject
KeywordPt/Rudc.subject
KeywordRu(0001)dc.subject
KeywordSpill-overdc.subject
KeywordTPDdc.subject
Dewey Decimal GroupDDC 540 / Chemistry & allied sciencesdc.subject.ddc
LCSHCarbon monoxidedc.subject.lcsh
LCSHPalladium alloysdc.subject.lcsh
LCSHSurfaces (Physics)dc.subject.lcsh
TitleAdsorption properties of bimetallic PdRu/Ru(0001) and Pt/Ru(0001) model catalyst surfacesdc.title
Resource typeDissertationdc.type
DOIhttp://dx.doi.org/10.18725/OPARU-2625dc.identifier.doi
PPN1653015373dc.identifier.ppn
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-vts-86748dc.identifier.urn
GNDAdsorptiondc.subject.gnd
GNDDeuteriumdc.subject.gnd
GNDKoadsorptiondc.subject.gnd
FacultyFakultät für Naturwissenschaftenuulm.affiliationGeneral
Date of activation2013-10-07T09:34:27Zuulm.freischaltungVTS
Peer reviewneinuulm.peerReview
Shelfmark print versionW: W-H 13.400uulm.shelfmark
DCMI TypeTextuulm.typeDCMI
VTS ID8674uulm.vtsID
CategoryPublikationenuulm.category
Bibliographyuulmuulm.bibliographie


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