Investigation of the catalytic behavior and chemical nature of alkali promoted copper and copper-cobalt-chromium oxide catalysts for the conversion of synthesis gas to methanol and higher alcohols

dc.contributor.advisor Terry S. King
dc.contributor.author Sheffer, Gordon
dc.contributor.department Chemical and Biological Engineering
dc.date 2018-08-16T06:04:57.000
dc.date.accessioned 2020-07-02T06:12:37Z
dc.date.available 2020-07-02T06:12:37Z
dc.date.copyright Thu Jan 01 00:00:00 UTC 1987
dc.date.issued 1987
dc.description.abstract <p>The work completed for this dissertation has endeavored to identify the active phase(s) for the synthesis of normal alcohols by carbon monoxide hydrogenation with the alkali promoted copper-cobalt-chromium catalyst system patented by the Institut Francais du Petrole. Initial work investigated the effects of a variety of preparation parameters on catalytic activity and selectivity. It was found that special attention must be paid to catalyst calcination temperature. At low calcination temperatures, alcohol selectivities as great as 70 wt % with a production yield of 0.12 g alcohol/g catalyst/hr were obtained. This is the greatest selectivity and yield yet to be found for this catalyst system outside of the inventors' laboratories. Using X-ray diffraction and X-ray photoelectron spectroscopy, the chemical nature of the catalyst was evaluated as a function of calcination temperature. The activated catalyst was comprised of copper metal and a cobalt-chromium spinel. Oxygenate production correlated with the dispersion of copper metal in the catalyst. Poorer copper dispersion and a decrease in oxygenate formation was observed with increasing calcination temperature. The picture of the active catalyst which evolved was that copper metal was supported on a cobalt-chromium spinel. This picture contrasts sharply with previous speculation that cobalt metal and copper(I) chromite were the active phases;An additional avenue of research which resulted from work with the copper-cobalt-chromium system was the investigation of alkali promotion of unsupported copper metal. Although copper metal alone was inactive for carbon monoxide hydrogenation, alkali promoted unsupported copper catalysts were found to be active and selective methanol synthesis catalysts. The methanol synthesis rate increased by an order of magnitude from Li to Cs. It was determined that the role of the alkali is to stabilize the formation of Cu[superscript]+ species, active centers for methanol synthesis. The differences in activity for the alkali series were found to be a result of differences in the concentration of Cu[superscript]+ species at the surface and not electronic effects.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/9303/
dc.identifier.articleid 10302
dc.identifier.contextkey 6355947
dc.identifier.doi https://doi.org/10.31274/rtd-180813-11903
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/9303
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/82388
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/9303/r_8805138.pdf|||Sat Jan 15 02:31:27 UTC 2022
dc.subject.disciplines Chemical Engineering
dc.subject.keywords Chemical engineering
dc.title Investigation of the catalytic behavior and chemical nature of alkali promoted copper and copper-cobalt-chromium oxide catalysts for the conversion of synthesis gas to methanol and higher alcohols
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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