X-ray photoelectron spectroscopic and in-situ infrared investigation of a Ru/SiO2 catalyst

Simple item page
buir.advisorSüzer, Şefik
dc.contributor.authorSayan, Şafak
dc.date.accessioned2016-01-08T20:14:55Z
dc.date.available2016-01-08T20:14:55Z
dc.date.issued1997
dc.departmentDepartment of Chemistryen_US
dc.descriptionAnkara : Department of Chemistry and the Institute of Engineering and Sciences of Bilkent University, 1997.en_US
dc.descriptionThesis (Master's) -- Bilkent University, 1997.en_US
dc.descriptionIncludes bibliographical references leaves 68-71.en_US
dc.description.abstractA 4 wt% Ru/Si02 catalyst which was previously prepared via an incipient wetness technique using a ruthenium nitrosyl-nitrate [Ru(N0)(N03)3] solution and a commercially available precursor (ruthenium nitrosyl-nitrate) were used in this study. The activation of the catalyst was investigated by using Infrared (IR) spectroscopy together with X-ray photoelectron spectroscopy (XPS). Special emphasis has been given to the study of formation of active species during annealing of the precursor and the catalyst for comparison purposes. The in-situ IR measurements performed on the catalyst suggested a possible metal and support interaction. XPS experiments revealed mixed oxidation states in the case of annealing of the precursor whereas annealing did not cause any change in the oxidation state of Ru present in the catalyst which lead to the conclusion that the influence of support and interactions between the metal and support prevented any reduction by annealing only. Carbon monoxide adsorption on the reduced catalyst followed by IR spectroscopy was performed to investigate the nature of active adsorption sites. The complexity of the spectrum of chemisorbed CO suggested the presence of small metal particles. The presence of Ru"^ centers as well as reduced Ru centers showed that the catalyst was not fully reduced under these conditions. Using this catalyst ammonia synthesis was achieved at 350 °C in a N2/H2 gas mixture (N2/H2 =3:1) for different reaction times. In addition to observed NH3 as reaction product, the results showed that NH^ surface species might represent intermediates in the ammonia synthesis reaction on Ru/Si02. Carbon monoxide adsorption on the catalyst after NH3 synthesis was performed to investigate the change in nature of active sites after ammonia production when compared with the reduced sample. Based on the experimental observations, participation of Ru° sites in ammonia synthesis was confirmed and a partial oxidation of the reduced Ru sites during synthesis was observed.en_US
dc.description.degreeM.S.en_US
dc.description.statementofresponsibilitySayan, Şafaken_US
dc.format.extentxvi, 71 leavesen_US
dc.identifier.itemidBILKUTUPB038380
dc.identifier.urihttp://hdl.handle.net/11693/17959
dc.language.isoEnglishen_US
dc.publisherBilkent Universityen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectX-ray photoelectron spectroscopy (XPS)en_US
dc.subjectInfrared spectroscopy (IR)en_US
dc.subjectCatalysten_US
dc.subjectAnnealingen_US
dc.subjectChemisorptionen_US
dc.subjectPrecursoren_US
dc.subjectMixed oxidation statesen_US
dc.subject.lccQC454.P48 S29 1997en_US
dc.subject.lcshPhotoelectron spectroscopy.en_US
dc.subject.lcshX-ray spectroscopy.en_US
dc.subject.lcshElectron spectroscopy.en_US
dc.titleX-ray photoelectron spectroscopic and in-situ infrared investigation of a Ru/SiO2 catalysten_US
dc.typeThesisen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
B038380.pdf
Size:
4.4 MB
Format:
Adobe Portable Document Format
Description:
Full printable version
Download
Collections
Dept. of Chemistry - Master's degree