37 research outputs found
Polymer Immobilised Ionic Liquid Supported Catalysts: Synthesis, Characterisation and Applications
PhD ThesisDue to increasing demand for synthetic commodities, to reduce the overall
environmental impact of existing chemical processes, a sustainable approach is
required. In order to accomplish this, it will be necessary to use highly efficient, durable,
and scalable catalyst technologies which are low in energy consumption and waste
production. In addition, bio-renewable feedstock will also be required due its
abundancy and availability. In this regard, chapter 1 provides an overview of the unique
physicochemical properties and concepts of ionic liquids (ILs). The incorporation of ILs
can produce functional materials, which in turn, can be used for the sustainable
conversion of bio-renewable feedstock.
Chapter 2 discusses the rational design and synthesis of a range of ruthenium
nanoparticle (RuNP) catalysts, in which, the catalysts were tested in the hydrogenation
of the benchmark substrate acetophenone. The overall aim of this work was to
investigate the effect of the interactions between the ruthenium and the polymer
support on the catalyst performance and selectivity. The resulting catalysts were highly
active and selective in the hydrogenation of a range of , -unsaturated ketones,
aldehydes, and the study was extended to include bio-derived substrates. In total four
reactions were tested, namely the hydrogenation of acetophenone, furfural, levulinic
acid and ethyl levulinate. The low ruthenium loadings and the reusability of these
heterogenous catalysts, in addition to the use of water as the co-solvent/solvent, has
provided a sustainable hydrogenation method, which is among one of the highest
reported on comparison with the literature. Chapter 3 covers the application of the
RuNPs for the hydrazine-mediated reduction of a broad range of nitroaromatics to their
corresponding aromatic amines under mild conditions with low catalyst loadings.
Chapter 4 details the synthesis of a set of imidazolium polystyrene-based
Brønsted acid catalysts immobilised with peroxophosphotungstate anions. These
efficient and selective catalysts were tested, as catalysts for the alcoholysis of furfuryl
alcohol to produce alkyl levulinates, under batch as well as continuous flow regimes.
Such generated levulinates are highly desirable as bio-renewable fuel additives