No description available.

No description available.

No description available.

The rising environmental and financial consequences of using fossil fuels as an energy source and energy carrier are a global concern. Described herein are two hydrogen-storing technologies, each of which was envisioned as a potential solution to said consequences: hydrogen-storing polymethylpyridylsiloxanes for use as an alternative energy carrier to fossil fuels; and thermally regenerative fuel cell systems to supplement or supplant vehicular alternators. A thermally regenerative fuel cell (TRFC) system is being developed to convert waste heat from an internal combustion engine (ICE) system into electricity that can be used to power auxiliary vehicular components. The TRFC system will comprise a dehydrogenation reactor and a fuel cell positioned relative to the ICE system such that the two components are held at 200 °C and 100 °C, respectively. 1-Phenyl-1-propanol has been identified as an optimal hydrogen storing liquid (XH2) that will selectively dehydrogenate over a heterogeneous catalyst to give a dehydrogenated liquid (propiophenone, X) and H2. The heterogeneous catalyst that currently provides the best selectivity (99.65%) for X at 200 °C is Pd/SiO2. A selectivity of ≥ 99.9% was desired to obtain the longest possible operational lifetime for the working fluids XH2/X. To increase the selectivity for X from 99.65% to ≥ 99.9%, size and shape specific Pd nanoparticles were synthesized. Pd nanocubes (20 nm) provided the best selectivity for X at 99.26%. It was concluded that a reproducible selectivity for X of ≥ 99.9% was not currently obtainable, and that a selectivity for X no greater than 99 % should be assumed when calculating the working fluids’ operational lifetime. Hydrogen-storing polymethylpyridylsiloxanes were proposed as energy carrier alternatives to fossil fuels. Polymethylpyridylsiloxanes were considered, in part, due to the expansive liquid ranges of siloxane polymers [-40 ˚C to 250 ˚C]; this would allow the polymethylpyridylsiloxanes to be stored and pumped into vehicles using existing refueling infrastructure. Polymethylpyridylsiloxanes, and analogs thereof, however, were not successfully synthesized and reversibly hydrogenated: either the desired product(s) could not be synthesized, isolated, and/or purified; or, hydrogenation resulted in product decomposition. It was concluded, therefore, that implementing polymethylpyridylsiloxanes as hydrogen-storing liquids is not viable. / Thesis (Ph.D, Chemistry) -- Queen's University, 2013-12-24 01:01:16.857

The addition of an aldehyde C−H bond across a ketone functionality, formally a hydroacylation, has emerged as an atom-economical approach to the synthesis of esters. While this is an efficient strategy for producing biologically-relevant materials, the field of transition metal-catalyzed ketone hydroacylation is currently limited to intramolecular systems. The development of a new rhodium catalyst will be presented, and its application to intermolecular ketone hydroacylation will be discussed. Ester products were synthesized from unfunctionalized, aliphatic aldehydes and chelating ketones in excellent yields under relatively mild reaction conditions. Efforts towards an asymmetric intermolecular ketone hydroacylation will be described, including the application of known chiral catalysts and the development of novel chiral phosphine ligands for asymmetric catalysis. Ester products were obtained in as high as 78% enantiomeric excess.

<p>Over the recent past, organometallic chemistry has grown and the impact of catalytic applications in various chemical technologies has rapidly evolved from the realm of academic laboratories into full-scale industrial processes. Pyrrole-imine ligands were prepared by condensation of pyrrole-2-carboxylaldehyde with propyl amine, 2,6-diisopropylanaline, poly(propylene) imine dendrimer and 3-aminopropyl-triethoxysilane to give the desired ligands in good yields. These ligands were charaterized via combination of techniques to establish the molecular structure. Microanalysis was performed to confirm the purity of the product.</p>

No description available.

No description available.

No description available.

A stable high temperature gold nano-catalyst: synthesis, characterization and application The ability of supported gold nanoparticles to catalyse many reactions even at very low temperatures has spurred a great deal of research into the eld. Reactions such as CO oxidation and NOx reduction have many industrial applications as well as uses in the motor industry for catalytic converters. The interest is both for scienti c as well as economic reasons as gold supplies far exceed all PGM supplies. Scienti cally gold catalysts are able to catalyze reactions from below 0°C, a feat that no PGM catalyst can achieve. The low temperature activity of gold catalysts will reduce the emission of pollutants during start up. Since the discovery and development of gold catalysts one of the most researched topics has been nding ways to stabilise the gold nanoparticles on the support surface. The importance of gold nanoparticle stability is crucial as the catalysts are only highly active if the gold nanoparticles are less than 5 nm in size. A number of companies have worked to develop gold catalysts that are stable for long durations at temperatures over 450°C with no signi cant progress made over the last two decades other than a catalyst produced by Toyota. In this thesis, literature reviews of current support materials as well as synthesis methods are investigated in order to determine reasons for the instability of current gold catalysts. Further, the Mintek Aurolite catalyst is tested and its deactivation mechanisms probed using in-situ VT-PXRD, Rietveld re nement, TEM, HR-TEM, as well as CO oxidation tests. Testing revealed aws in the support structure of the catalyst which resulted in dramatic deactivation. As titania is such a common support material for many reactions in industry as well as being known to be one of the best supports for gold it was chosen as a support material. However, as is revealed, in its current forms and morphologies it is unable to provide the thermodynamically stable and high surface areas that are required for a stable catalyst After the development of a robust and reproducible synthesis method for the deposition of gold and other PGM's a number of supports were tested. These include silica and zirconia as well as titania derivatives such as Degussa P25 and commercial anatase. Initially these supports o er high usable surface areas but after a relatively small amount of time complete deactivation occurs. Reasons for this deactivation are determined and the information gained is used to develop supports that can combat these deactivation processes. Phase pure nano anatase is synthesised which produced a support with an incredibly large surface area compared to the aforementioned supports. The catalyst was able to withstand temperatures over 450°C for longer durations compared to other catalysts exposed to the same conditions. However, the phase conversion of the anatase to its thermodynamically stable form rutile once again deactivated the catalyst with time. Finally a rutile nanosupport is developed with the desired morphology and thermodynamic stability needed for high temperature applications. The catalyst is able to withstand temperatures over 550°C for more than 200 hours as well as still being active after exposure to 810°C. The industrial Aurolite catalyst showed complete deactivation after just 12 hours at 500°C. The catalyst produced in this thesis has been shown to be one of the most stable and thermally resistant gold catalysts in the world.