Surface-supported Ag islands stabilized by a quantum size effect: their interaction with small molecules relevant to ethylene epoxidation

dc.contributor.advisor Patricia A. Thiel
dc.contributor.author Shao, Dahai
dc.contributor.department Chemistry
dc.date 2018-07-22T23:03:41.000
dc.date.accessioned 2020-06-30T02:49:01Z
dc.date.available 2020-06-30T02:49:01Z
dc.date.copyright Tue Jan 01 00:00:00 UTC 2013
dc.date.embargo 2015-07-30
dc.date.issued 2013-01-01
dc.description.abstract <p>Surface-supported Ag nanoparticles demonstrate quantum-size-effect (QSE) mediated growth behavior. 2-layer Ag islands are stabilized by QSE for Ag/Si(111)-7x7. O2 exposure on such system changes the Ag island height distribution: promoting 3-layer island growth at the expense of 1-, and 2-layer islands. This is an indication that oxygen adsorption changes QSE of Ag/Si(111)-7x7. Mild annealing following O2 exposure promotes growth of even higher islands (up to 9-layer high). Such trend indicates the instability of 3-layer islands with oxygen adsorption. Ethylene exposure on Ag/Si(111)-7x7 leads to protrusions on Ag islands and protrusive rims on island edges. But ethylene does not affect QSE of Ag/Si(111)-7x7 significantly. O2 exposure on Ag/NiAl(110) disrupts the relative stability of Ag bilayer (BL) islands stabilized by QSE. 1-BL island react with O2 to form indentations and protrusions. However, these features do not occur on 2-BL Ag islands. A possible explanation is that the adsorption energy of oxygen is much higher on 2-BL islands than on 1-BL islands.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/13338/
dc.identifier.articleid 4345
dc.identifier.contextkey 4615837
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/13338
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/27526
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/13338/Shao_iastate_0097E_13684.pdf|||Fri Jan 14 19:50:20 UTC 2022
dc.subject.disciplines Chemistry
dc.subject.keywords Ag/NiAl(110)
dc.subject.keywords Ag/Si(111)-7x7
dc.subject.keywords chemisorption
dc.subject.keywords ethylene epoxidation
dc.subject.keywords oxygen
dc.subject.keywords quantum size effect
dc.title Surface-supported Ag islands stabilized by a quantum size effect: their interaction with small molecules relevant to ethylene epoxidation
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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