Metal cluster hydrodesulfurization catalysts based on ternary molybdenum sulfides

dc.contributor.advisor Glenn L. Schrader
dc.contributor.author Thompson, Robert
dc.contributor.department Chemical and Biological Engineering
dc.date 2018-08-22T21:38:10.000
dc.date.accessioned 2020-06-30T07:18:53Z
dc.date.available 2020-06-30T07:18:53Z
dc.date.copyright Fri Jan 01 00:00:00 UTC 1999
dc.date.issued 1999
dc.description.abstract <p>Catalysts based on metal sulfide cluster compounds such as Chevrel phases (MxMo6S8) have been shown to possess high activity and selectivity for hydroprocessing reactions. Previous methods of preparing crystalline Chevrel phases have involved high temperature, solid-state synthetic routes which produce low surface area materials (0.1--1.0m2/gm). In our recent research, lower temperature syntheses via solution precursors have been explored as routes to these materials. The discovery of a new class of compounds, M2x/n n+(Mo6S8)Sx (n = 1--3) has resulted. These new reduced ternary molybdenum sulfides have been shown to have both high activity and selectivity in HDS reactions with thiophene, while also exhibiting initial surface areas near 200m2/gm. The stability and activity of these materials is dependent upon the pretreatment procedure. Surface area and porosity data have revealed a decrease in surface area and an increase in average pore size as the pretreatment temperature is increased. Temperature-programmed analysis studies were performed in conjunction with XPS to examine how the oxidation states change as a function of pretreatment temperature. The mechanism through which these new reduced ternary molybdenum sulfides convert to the crystalline Chevrel phase was also determined;The low temperature synthesis route of these new reduced molybdenum sulfides has allowed the synthesis of new cluster compounds, such as Pt(Mo6S8 )S. X-ray photoelectron spectroscopy, laser Raman spectroscopy, infrared spectroscopy and microprobe analysis indicate that this new material is structurally similar to other cluster compounds we have synthesized. Pretreatment of PtMoS in hydrogen at 950°C results in its conversion to the previously unknown crystalline Chevrel phase.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/12174/
dc.identifier.articleid 13173
dc.identifier.contextkey 6766915
dc.identifier.doi https://doi.org/10.31274/rtd-180813-13451
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/12174
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/65513
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/12174/r_9940246.pdf|||Fri Jan 14 19:14:34 UTC 2022
dc.subject.disciplines Chemical Engineering
dc.subject.disciplines Inorganic Chemistry
dc.subject.keywords Chemical engineering
dc.title Metal cluster hydrodesulfurization catalysts based on ternary molybdenum sulfides
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 86545861-382c-4c15-8c52-eb8e9afe6b75
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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