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Iridium-4'-Phenyl-Terpyridine, Ruthenium-Triphos, and Ruthenium-N-Triphos Complexes as Homogeneous Catalysts for Hydrogenation of Biomass-Derived Substrates in Aqueous Acidic Medium at High Temperature

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dc.contributor.advisor Schlaf, Marcel
dc.contributor.author Latifi, Elnaz
dc.date.accessioned 2017-09-11T19:18:27Z
dc.date.available 2018-09-05T05:00:42Z
dc.date.copyright 2017-09
dc.date.created 2017-09-05
dc.date.issued 2017-09-11
dc.identifier.uri http://hdl.handle.net/10214/11573
dc.description.abstract In order to convert overfunctionalized biomass-derived compounds into chemicals and fuels a catalyst is needed to effect hydrodeoxygenation (HDO), i.e., the combination of iterative acid-catalyzed dehydration and metal catalyzed hydrogenations/hydrogenolysis to decrease the content of oxygen. To meet this goal, the complexes [(4'-Ph-terpy)Ir(OTf)3] (4'-Ph-terpy = 4'-phenyl-2,2':6'6"-terpyridine) and [Ru(triphos)(CH3CN)3](OTf)2 (triphos = 1,1,1-tris(diphenylphosphinomethyl) ethane) were prepared and evaluated as water-, acid- and high-temperature stable homogeneous catalysts for the hydrogenation of biomass-derived 2,5-hexanedione and 2,5-dimethylfuran (2,5-DMF) to value added chemicals. At T ≥ 175 °C the iridium system decomposed to a combination of a highly active heterogeneous Ir0 on the reactor walls and an inactive [M(4'-Ph-terpy)2]n+ compound (M = Fe, Ni, Ru, Ir; n = 2, 3) characterized by ESI-MS and single crystal X-ray crystallography, in which the source of the Fe and Ni was metal leaching from the 316SS reactor body. [Ru(triphos)(CH3CN)3](OTf)2 on the other hand was an effective homogeneous catalyst for the hydrogenation of 2,5-hexanedione and 2,5-DMF at temperatures between 150 and 200 °C. This catalyst became deactivated by formation of the bridging compound [Ru2(μ-OH)3(triphos)2](OTf), but could be reactivated by the addition of an acid co-catalyst. The hydrogenation of 2,5-hexanedione showed a first order rate dependence on hydrogen pressure as determined by direct hydrogen uptake rate measurements. With furfuryl alcohol — a more challenging substrate — only marginal conversions to hydrogenated products were observed. In an attempt to improve the catalyst activity by improving the water solubility, [Ru(NCCH3)3(N-triphos)](CF3SO3)2 was prepared and was able to convert furfuryl alcohol to 1,4-pentanediol in modest yield (26%), but still exhibited lower than desired water solubility under either neutral or acidic conditions at room temperature. en_US
dc.language.iso en en_US
dc.rights Attribution-NonCommercial 2.5 Canada *
dc.rights.uri http://creativecommons.org/licenses/by-nc/2.5/ca/ *
dc.subject Iridium en_US
dc.subject Ruthenium en_US
dc.subject Hydrogenation en_US
dc.subject Hydrodeoxygenation en_US
dc.subject Triphos en_US
dc.subject Furfuryl alcohol en_US
dc.subject 2,5-dimethylfuran en_US
dc.subject High pressure en_US
dc.subject Kinetics en_US
dc.title Iridium-4'-Phenyl-Terpyridine, Ruthenium-Triphos, and Ruthenium-N-Triphos Complexes as Homogeneous Catalysts for Hydrogenation of Biomass-Derived Substrates in Aqueous Acidic Medium at High Temperature en_US
dc.type Thesis en_US
dc.degree.programme Chemistry en_US
dc.degree.name Doctor of Philosophy en_US
dc.degree.department Department of Chemistry en_US
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