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This thesis describes the design and commissioning of a fixed bed flow reactor and its subsequent application in the screening of novel and modified sheet aluminosilicate catalysts for the acid catalysed alkylation of benzene with propene. The flow reactor was developed to study this reaction in the liquid phase at temperatures between 100 and 250 degrees centigrade and pressures between 10 and 50 bar. Batch reactions of benzene and propan-2-ol were used as an analogy for the commercial reaction of alkene and benzene, and showed that the expected di- and trisubstituted aromatics undergo isomerisation and trans alkylation reactions at 200 degrees centigrade over an acid exchanged montmorillonite mineral. In the flow reactor experiments, proton exchanged varieties of several minerals were screened for activity, and the variety known as Texas montmorillonite was chosen for more detailed study. These studies included the effects of different exchanged cations in the clay and that of varying reaction temperature, high liquid hourly space velocity and selective poisoning and with an organic base. Structural modifications to the catalyst were also considered in pillaring and charge reduction experiments. Ethylbenzene, is an undesirable by-product and an extensive study of the factors influencing cumene/ethylbenzene selectivity are detailed in the latter part of this work. Finally, the performance of the most promising catalysts in transalkylation reactions led to the identification of two of the modified catalysts used here as offering advantages over the present commercially employed catalyst.

The catalytic reactions of a wide range of organic compounds with ion-exchanged bentonites have been investigated. Subsequent product analysis by modern analytical methods including gas-liquid chromatography, mass spectrometry, the combined technique of gas chromatography and mass spectrometry and nuclear magnetic resonance has established that a number of the catalytic reactions discovered are unique in the sense that although nominally feasible in solution reaction systems, they do not, in practice, occur. This research has shown that alkenes can react with intercalated water in the sheet silicate to produce branched chain ethers and that both alkanols and carboxylic acids can react with alkenes under the influence of the sheet silicate catalyst to furnish high yields of ethers and esters respectively. The sheet silicate has also been shown to catalyse the self condensation of alkan-1-ols to ethers, primary amines to secondary amines and thiols to thioethers. Benzyl alcohol and 2-hydroxymethylthiophene have been converted by the influence of the catalyst into high polymeric materials by self condensation processes. The work has revealed that a wide range of both known and novel types of organic chemical reactions are efficiently catalysed by certain cation-exchanged bentonites and that intercalation is a prerequisite. From this survey a mechanistic generalisation has emerged in which the role of protons in the catalysis is crucial and the attack of a nucleophile on a protonated species is a key mechanistic process.

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Environmental concerns and more stringent regulations have stimulated the development of new cleaner technologies to decrease the emissions of greenhouse gases and other hazardous gas emissions. In this study, the steam reforming of biooil as well as NOx storage and reduction catalysts were investigated. The production of hydrogen by steam reforming of bio-oils obtained from the fast pyrolysis of biomass requires the development of efficient catalysts able to cope with the complex chemical nature of the reactant. Steam reforming of a few model compounds and that of an actual bio-oil was investigated in the temperature range 650-900°C over Pt, Pd and Rh supported on alumina and a ceria-zirconia sample. The use of ceria-zirconia led to higher H2 yields. The supported Rh and Pt catalysts were the most active, while palladium-based catalysts performed poorly. Temperatures close to, or higher than, 800°C were required to achieve significant conversions to COx and H2 (e.g., H2 yields around 70%) ofthe bio-oil. NOx Storage and Reduction (NSR) catalysts are considered to be one of the most promising solutions to meet the upcoming NOx exhaust emission regulations. However, despite the high level of activity in this area, it is surprising that most studies have been conducted under conditions that are far from realistic. A fast transient apparatus has been developed to study these catalysts under realistic temporal conditions. The performance of a typical Pt/Ba/y-Ah03 NSR catalyst was studied as a function ofthe temperature, rich phase duration, reductant concentration, the type of reductant and the space velocity and the importance of the regeneration step in the NSR process was highlighted. The regeneration step was further investigated over Pt and/or Rh based catalysts by coupling of fast transient kinetic switching and the use of 15NO. An unexpected double peak in the evolution of nitrogen was revealed. The first peak occurred immediately on switching from lean to rich conditions, while the second peak started at the point at which the gases switched from rich to lean. Rh/Ba/Ah03 trap was found to be dependent on the rate of NOx storage, since the rate of regeneration was sufficient to remove the NOx stored in the lean phase. pt/Ba/Al203 was found to be limited by the rate of regeneration.

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