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dc.contributor.authorKaratok, Mustafa
dc.contributor.authorŞensoy, Mehmet Gökhan
dc.contributor.authorVovk, Evgeny
dc.contributor.authorÜstünel, Hande
dc.contributor.authorToffoli, Daniele
dc.contributor.authorÖzensoy, Emrah
dc.date.accessioned2022-09-12T10:41:12Z
dc.date.available2022-09-12T10:41:12Z
dc.date.issued2021en_US
dc.identifier.citationKaratok, M. Sensoy, M.G., Vovk, E., Ustunel, H., Toffoli, D.& Ozensoy, E. (2021). Formaldehyde Selectivity in Methanol Partial Oxidation on Silver: Effect of Reactive Oxygen Species, Surface Reconstruction, and Stability of Intermediates. ACS Catalysis, 11(10), 6200-6209. https://doi.org/10.1021/acscatal.1c00344en_US
dc.identifier.issn2155-5435
dc.identifier.urihttps://doi.org/10.1021/acscatal.1c00344
dc.identifier.urihttps://hdl.handle.net/11436/6438
dc.description.abstractSelective oxidation reactions on heterogeneous silver catalysts are essential for the mass production of numerous industrial commodity chemicals. However, the nature of active oxygen species in such reactions is still debated. To shed light on the role of different oxygen species, we studied the methanol oxidation reaction on Ag(111) single-crystal model catalyst surfaces containing two dissimilar types of oxygen (electrophilic, O-e and nucleophilic, O-n). X-ray photoelectron spectroscopy and low energy electron diffraction experiments suggested that the atomic structure of the Ag(111) surface remained mostly unchanged after accumulating low O-e coverage at 140 K. Temperature-programmed reaction spectroscopic investigation of low coverages of O-e on Ag(111) revealed that O-e was active for methanol oxidation on Ag(111) with a high selectivity toward formaldehyde (CH2O) production. High surface oxygen coverages, on the other hand, triggered a reconstruction of the Ag(111) surface, yielding Ag oxide domains, which catalyzes methanol total oxidation to CO2 and decreases the formaldehyde selectivity. This important finding indicates a trade-off between CH2O selectivity and methanol conversion, where 93% CH2O selectivity can be achieved for an oxygen surface coverage of theta(O) = 0.08 ML (ML = monolayer) with moderate methanol conversion, while methanol conversion could be boosted by a factor of similar to 4 for theta(O) = 0.26 ML with a suppression of CH2O selectivity to 50%. Infrared reflection absorption spectroscopy results and density functional theory calculations indicated that Ag oxide contains dissimilar adsorption sites for methoxy intermediates, which are also energetically less stable than that of the unreconstructed Ag(111). The current findings provide important molecular-level insights regarding the surface structure of the oxidized Ag(111) model catalyst directly governing the competition between different reaction pathways in methanol oxidation reaction, ultimately dictating the reactant conversion and product selectivity.en_US
dc.description.sponsorshipTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) 112T589 Republic of Turkey Presidential Directorate of Strategy and Budget 2006K12-827en_US
dc.language.isoengen_US
dc.publisherAmer Chemical Soc.en_US
dc.rightsinfo:eu-repo/semantics/closedAccessen_US
dc.subjectMethanol oxidationen_US
dc.subjectSelective catalytic oxidationen_US
dc.subjectSilver catalysten_US
dc.subjectFormaldehydeen_US
dc.subjectAtomic oxygenen_US
dc.titleFormaldehyde selectivity in methanol partial oxidation on silver: effect of reactive oxygen species, surface reconstruction, and stability of intermediatesen_US
dc.typearticleen_US
dc.contributor.departmentRTEÜ, Fen - Edebiyat Fakültesi, Fizik Bölümüen_US
dc.contributor.institutionauthorŞensoy, Mehmet Gökhan
dc.identifier.doi10.1021/acscatal.1c00344en_US
dc.identifier.volume11en_US
dc.identifier.issue10en_US
dc.identifier.startpage6200en_US
dc.identifier.endpage6209en_US
dc.relation.journalACS Catalysisen_US
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanıen_US


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