Ionic liquids (ILs) have been paid particular interest in the field of catalysis over the past 2 decades, offering not only enhancements in catalyst performance but also the ability to heterogenise molecular species and effectively combine the benefits homogenous and heterogeneous catalysis. Although advantageous, significant limitations remain, particularly with respects to leaching and mass transport. As a result the heterogenisation of IL moieties, in the form of the Supported Ionic Liquid Phase (SILP), has been widely investigated to avoid these issues. By extension of the SILP concept, polymer materials can offer additional benefits through the well-defined, controllable nature of polymer chemistry. The work presented herein focuses on the application of pre-fabricated ionic liquid tagged monomers to prepare well-defined polymer supports under mild, controllable conditions, termed the Polymer Immobilised Ionic Liquid Phase (PIILP). These well-defined materials were then used to support various homogeneous catalytic species as a means to give highly active, recyclable systems which effectively combine the positive aspects of homogeneous and heterogeneous catalysis with the enhancement effects associated with ionic liquids. Chapter 1 discusses the use of ionic liquids, SILP and PIILP-type systems in catalysis across the literature, before briefly assessing common polymerisation methods in order to determine the most suitable means to prepare PIILP materials. The initial evaluation of the PIILP methodology is discussed in chapter 2, wherein a linear pyrrolidinium-functionalised support was prepared by ring-opening metathesis polymerisation (ROMP). The resulting material was used to immobilise a peroxophosphotungstate species to give a heterogeneous catalyst which was highly active in epoxidation, alcohol oxidation and sulfoxidation reactions under relatively mild conditions with H2O2 as the oxidant. Chapter 3 discusses the implementation of the PIILP-catalysed sulfoxidation chemistry under continuous flow conditions, with the promising performance highlighting the potential application of PIILP in the preparation of pharmaceutical intermediates and in the purification of crude oil. In chapter 4 cross-linked polystyrene-based PIILP materials are shown to be effective supports in asymmetric Diels-Alder and Mukaiyama-Aldol reactions, with PIILP supports giving enhancements in ee compared to analogous IL and SILP systems. Similarly, in chapter 5 polystyrene-based supports are effectively used to immobilise Pd nanoparticles whilst also investigating the effect of heteroatom donating co-monomers. Although moderately promising catalytic performance was observed in a range of Suzuki Miyaura couplings, no clear trends with regards to nanoparticle size and catalyst performance were noted. The results obtained throughout this thesis highlight the vast potential of the PIILP methodology in heterogeneous catalysis, however the incredibly complex nature of the relationship between the catalyst, support and substrate makes it difficult to fully rationalise performance trends. As such, further, more extensive studies into the support properties will be required to realise PIILP to its fullest potential.

The thermodynamic modelling of phase equilibrium is of central importance in chemical engineering applications. The design, operation and develop- ment of new chemical processes is based to a large extent on the knowledge of the equilibrium that occurs between co-existing fluid phases. Where re- liable experimental data at required process conditions is unavailable, an understanding of the molecular description of condensed phase matter is key to predicting the thermodynamic properties of these fluid systems. To this end, numerous models and theories have been developed that seek to link microscopic intermolecular interactions with bulk macroscopic thermo- dynamic properties. In this thesis, two such constructs for the prediction of phase equilibrium are considered. The empirical linear solvation energy relationship (LSER) that relates specific/unspecific intermolecular interac- tions to infinite dilution solute properties, and equations of state (EoS) for the prediciton of vapour-liquid and liquid-liquid equilibrium. The LSER model utilises hydrogen bond acceptor/donor parameters (A and B) alongside polarisability (S), volume (V) and molar refraction (E) param- eters to describe various solute properties. In this study, the prediciton of solute infinite dilution partititon coefficient is of particular interest. While the V and E parameters can be obtained from molecular structure calcula- tions that account for the number of atoms and bonds in a molecule, the re- maining LSER parameters are usually derived from chromatographic experiments. However, successive studies have successfully correlated and pre- dicted the hydrogen bonding parameters from quantum mechanical (QM) calculated molecular properties, enabling the rapid calculation of infinite dilution solute properties in the so-called QM/LSER approach. In this the- sis, two independent linear regression relationships that relate theoretically calculated hydrogen bond stabilisation energies at a donor and/or acceptor site(s) to experimental hydrogen bonding ability of a solute molecule have been determined. Once obtained, the solute hydrogen bonding parameters are used in conjunction with dispersion and volume parameters in the LSER to obtain solute partition coefficients. Using this approach ,the octanol/wa- ter partition coefficients of various molecules have been estimated, of this, the absolute average error of a sub-set of straight chained, mono-functional solute molecules has been determined to be 23.04% when compared to ex- perimental data. The second approach to modeling condensed phased matter is based on the statistical associating fluid theory (SAFT), a molecular-based equation of state with a foundation in statistical mechanics. Here, a recently devel- oped group-contribution version i.e., SAFT-1 is considered. The SAFT-1 EoS has been successfully applied in the prediction of the octanol/water patition coefficients of a range of solute molecules that include n-alkane, n-alkene, 2- ketone and n-amine molecules. Where the average absolute error of SAFT- 1 predicitons when compared to experimental data is found to be 13.20%. However, as with other EoS, SAFT-1 is dependent on experimental data re- quired to parameterise the various groups that make up the fluid/fluid mix- ture under investigation. The aim of this work is to increase the predictive ability of SAFT-1 by reducing dependence on experimental data, whereby in- stead of equilibrium data, solute partition coefficients estimated using the QM/LSER method are used to parameterise the relevant molecular groups. In the final part of the thesis, the proposed hypothesis of combining the QM/LSER and SAFT-1 methods is tested with the aim of predicting the phase behaviour of binary mixtures. The method relies on the calculation of partition coefficients using QM and LSER, the calculated partition coef- ficients are then used to parameterise the unlike group-group interactions required for the prediction of binary mixture behaviour in SAFT-1. This methodology has been validated using the n-aldehyde and 2-ketone chemi- cal families, where using QM/LSER to parameterise SAFT-1 has been found to achieve results that are comparative to the classical empirical approach of parameterising the SAFT-1 EoS when predicting binary phase behaviour. The unlike group interaction parameters for the SAFT-1 EoS have been suc- cessfully parameterised using partition coefficient data estimated from the- oretically calculated quantum mechanical molecular properties. However, the solutes considered in this study are limited to linear mono-functional molecules. The reason for this limitation is two fold. Firstly, predicting hydrogen bond parameters of multi-functional molecules is unreliable mainly as a consequence of polarisation of H-bond sites due to the proximity of functional groups. Therefore a better understanding of how polarisation affects hydrogen bonding is required. Secondly, within SAFT-1 the major- ity of available groups are for modeling linear mono-functional molecules. However there is continuing work to model both branched and multifunc- tional molecules. Once both of these concerns are effectively dealt with, the proposed methodology can be used to characterize a wider range of SAFT- 1 groups and predict thermodynamic behaviour of molecules based on QM molecular calculations.

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A model has been developed for the simulation of the motion of unattached particles through foams. The model uses previous work on the bulk drainage of liquid through foams (Verbist et al., 1996) in addition to a velocity profile equation which describes the local variation in liquid velocity over the Plateau border cross section (Sparrow and Loeffler, 1959). These descriptions of the liquid flow on two separate scales are combined with realistic foam structures (provided by Kraynik, 2004) to form a description of the liquid flow through the foam. This liquid flow description is used as a basis for the simulation of particle motion through the interconnected network of Plateau borders and vertices of the foam. The results of the particle motion simulation model have been used to calculate the dispersion of particles through the foam. The model was used to replicate experiments performed by Lee (2004) on the forced drainage of liquid and particles in a laboratory scale foam column. From the results of this replication it is possible to predict axial dispersion coefficients which are validated with experimental data. It is also possible to use the model to perform a sensitivity analysis to determine which parameters have the greatest effect on the particle motion and dispersion and therefore merit further investigation. For instance, the model has been used to calculate the effect of particle size on axial dispersion through the foam. Finally, a geometric dispersion coefficient has been calculated for the three› dimensional, random, monodisperse foam structure used in the simulations. This is an improvement on the previous coefficient calculation method which used a two› dimensional, regular foam structure. The calculated value of the geometric dispersion coefficient corresponds closely to a value predicted based solely on the foam structure used in the simulations. This further highlights the already known dependence of geometric dispersion on foam structure.

Perovskite oxides such as manganites are considered to be strong candidates for appli- cations in magnetic refrigeration technology, due to their remarkable magnetocaloric properties, in addition to low processing costs. Manganites with the general formula R1-x AxMnO3, particularly for A=Ca and 0.2 < x < 0.5, undergo a field driven tran- sition from a paramagnetic to ferromagnetic state, which is accompanied by changes in the lattice and electronic structure. Therefore, one may anticipate a large entropy change across the phase transition due to the first order nature. Despite many ex- perimental efforts to enhance the isothermal entropy change in manganites, the max- imum obtained value merely reaches a modest value in the field of a permanent mag- net. The present work aims to achieve an understanding of the relevant structural, magnetic, and electronic energy contributions to the stability of the doped compound La0.75Ca0.25MnO3 . A combination of thermodynamics and first principles theory is applied to determine individual contributions to the total entropy change of the system by treating the electronic, lattice and magnetic components independently. For this purpose, hybrid-exchange density functional (B3LYP) calculations are performed for LaMnO3, CaMnO3 and La0.75Ca0.25MnO3 . The most stable phases for the end-point compounds are described correctly. Computed results for the doped compound predict an anti-Jahn-Teller polaron in the localised hole state, which is influenced by long- range cooperative Jahn-Teller distortions. The analysis of the energy scales related to the magnetocaloric effect suggests that the charge, orbital, spin and lattice degrees of freedom are strongly coupled, since they are of a similar magnitude. Through the analysis of individual entropy contributions, it is identified that the electronic and lat- tice entropy changes oppose the magnetic entropy change. Therefore, the electronic and vibrational terms have a deleterious effect on the total entropy change. The results highlighted in the present work may provide a useful framework for the interpretation of experimental observations as well as valuable guidelines for tuning the magnetocaloric properties of oxides, such as manganites.

In this thesis we investigate the recently developed Full Configuration Interaction Quantum Monte Carlo (FCIQMC) method. This method, unlike the traditional methods in Quantum Monte Carlo (QMC), doesn't require the use of the uncontrolled fixed node approximation and so potentially it can yield far more accurate results. This means that it can be thought of as a hybrid between the methods used by quantum chemists and QMC, and thus has spawned a new field of stochastic quantum chemistry. The work described in this thesis can be split into three distinct but interrelated parts. We begin with an investigation of the underlying FCIQMC stochastic process. We show that FCIQMC is an example of Markov Chain Monte Carlo. This means we can compute a stochastic matrix from which all details about the Monte-Carlo simulation can be obtained. Unfortunately the size of the space scales unfavourably as a function of system size meaning that we have only managed to compute the matrix for the smallest interesting two determinant system. We then use these results to quantify population control bias in FCIQMC for a two determinant system supplementing these analytical results with empirical results to investigate more realistic systems. We then attempt to quantify the efficiency of the FCIQMC algorithms, defining a measure of efficiency. After this we investigate the dependence of our measure on the system size. The error bar of the most efficient FCIQMC algorithm will decay fastest as a function of computer time. We then draw conclusions about the applicability of the FCIQMC method. Finally we describe an implementation of FCIQMC on a novel data flow computer architecture. In our implementation we made a modification to the FCIQMC algorithm to fit the data flow paradigm. We investigate the efficiency of the modified FCIQMC algorithm.

High availability and low price of crude glycerol, the main by-product of the biodiesel industry, make it an attractive feedstock for transformations into value-added chemicals. The aim of this thesis was to improve our understanding of the hydrothermal conversion of glycerol facilitated by zeolite-based catalysts. A range of Lewis acidic Ce-, La-, Sn- and Zn-doped ZSM-5 and Beta zeolites were prepared by solid state ion exchange reaction. The effect of those catalysts as well as their parent NH4- and H-forms on the dehydration of glycerol was investigated under hydrothermal conditions (270-360 °C, 55-186 bar, 5-300 min) in batch tubular reactors. Several reaction products were detected, of which acrolein was the main liquid product with the highest selectivity of ~38 mol% achieved within the first 5 min at 330 °C on H-Beta zeolite. At longer reaction times acrolein decomposed and acetaldehyde became the main product (max. selectivity ~26 mol% in 30 min). The addition of metal-doped zeolites did not increase the degree of glycerol conversion but increased the total selectivity towards the liquid products. 4.8 wt% La-doped NH4-Beta zeolite resulted in a 56 mol% glycerol conversion with a 36 mol% selectivity towards acetaldehyde. The oxidation of glycerol with H2O2 in subcritical water was investigated in a continuous fixed bed reactor at 125-175 °C, 35 bar, 60-300 s using H-Beta zeolite, 2.5 wt%- and 4.8 wt% Cu-doped H-Beta zeolite extruded with γ-Al2O3. As compared to non-catalysed oxidation, the addition of Cu-doped H-Beta zeolites did not increase the degree of conversion but promoted the conversion rate of glycerol as well as the selectivity towards liquid products. The liquid products detected included dihydroxyacetone (DHA), formic acid (FA), acetic acid, glycolic acid, pyruvaldehyde and lactic acid (LA). The distribution of these products varies with the temperature, residence time and the type of catalyst. The top-three main products obtained were DHA, FA and LA. The highest yield of DHA (~8 mol%) was achieved with 4.8 wt% Cu/H-Beta/γ-Al2O3 (MC) at 150 °C, 60 s. The same catalyst also provided LA with the highest yield of 11.5 mol% at 175 °C, 240 s. FA was detected with the highest yield of ~9 mol% at 175 °C, 60 s on H-Beta/γ-Al2O3 (MC).

Anodic dissolution of 12 metals and alloys was carried out in ionic liquids, a deep eutectic solvent comprising of 1:2 molar ratio mixture of choline chloride, [(CH₃)₃NC₂H₄OH] Cl, (ChCl) and ethylene glycol (EG) and C₄mimCl using electrochemical techniques, such as anodic linear sweep, chronoamperometry and chronopotentiometry. To study the dissolution mechanism electrochemical impedance spectroscopy (EIS) was used, in addition, a wide range of spectroscopic, for instance, UV-Visible and X-ray photoelectron spectroscopy (XPS) and microscopic techniques, such as scanning electron microscopy (SEM), atomic force microscopy (AFM) and 3D Optical microscopy were used. The anodic dissolution of copper in Ethaline and C₄mimCl was studied. It is shown that the speciation of dissolved copper at the interface region are [CuCl₃]⁻ and [CuCl₄]²⁻ and the EG controls the structure of interface. A super-saturated solution forms at the electrode-solution interface and CuCl₂ was deposited on the metal surface. The impact of additives, such as water and CuCl₂.2H₂O on the copper dissolution in Ethaline were examined. The former affected the quality of electropolished copper and the latter decreased the dissolution rate. The second stage of the study involved the study of eight metals, Ag, Au, Co, Fe, Ni, Pb, Sn and Zn in Ethaline and C4mimCl at 20 °C and 70 °C. Film formation occurred on almost all metals surface. It was only when the film that formed led to a diffusion controlled dissolution rate that electropolishing occurred. This was the case with nickel and cobalt in Ethaline at 20C producing a mirror finished surface. In the final section the anodic dissolution of three alloys; Cu₀.₆₃Zn₀.₃₇, Cu₀.₉₄Sn₀.₀₆, and Cu₀.₅₅Ni₀.₄₅ was studied in Ethaline at 20 °C. The Cu₀.₉₄Sn₀.₀₆ and Cu₀.₅₅Ni₀.₄₅ showed electropolishing whereas Cu₀.₆₃Zn₀.₃₇ displayed dealloying. The redox potential difference and the elemental composition of the alloys controlled the dissolution mechanism. The electropolishing mechanism was shown to be consistent with the model developed in Chapter 4.

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