Research on the co-feeding of ammonia into the Fischer-Tropsch (FTS) process over ironbased catalysts revealed that the presence of ammonia during the FTS leads to the formation of nitrogen-containing compounds (NCCs). Recent studies on the addition of ammonia to the FTS process, now known as the Nitrogen Fischer-Tropsch (NFTS) process, reported that the production of NCCs during the NFTS process is enhanced by the presence of oxygenates. The studies, therefore, suggested that oxygenates are the primary precursors of NCCs. However, due to the gap in knowledge related to the NFTS reactions mechanisms, the validity of this assumption is still unknown. In this thesis, the aim was to investigate the correlation between the presence of oxygenates under the FTS conditions and the formation of NCCs under the NFTS conditions and check the suitability of various iron-based catalysts for the NFTS process. From literature, four ironbased catalysts, known for yielding a high percentage of oxygenates, were identified, synthesised, characterised and then tested under FTS conditions to determine the optimum reaction conditions for oxygenates formation. It was found that high oxygenates selectivity can be achieved at low temperature and high space velocity as at these operating conditions the occurrence of secondary reactions involving oxygenates are limited. Furthermore, the catalysts were tested under NFTS conditions to determine their catalytic performance and their selectivity towards NCCs. During the NFTS process, in addition to the decrease in the CO conversion, a significant drop in the oxygenates and CO2 selectivity followed by the formation of NCCs were observed. These results confirmed a sight activity inhibiting effect of ammonia and pointed out the correlation between the presence of oxygenates and the formation of NCCs under FTS and NFTS processes respectively. At the conditions applied, selectivities of up to 17.9 C% of NCCs (predominantly nitriles) could be obtained. This modified process may therefore be considered as an important variation of the FTS process with greatly enhanced chemicals production potential.

This research studies the use of class=SpellE>titania (titanium dioxide, TiO2) as a catalyst for deoxygenation of class=SpellE>syngas derived oxygenates. These oxygenates are formed as byproducts when biomass derived syngas (CO & H2) is converted to ethanol on Rhodium or Molybdenum based catalysts. Conversion of these oxygenates to hydrocarbon would enhance the viability of class=SpellE>syngas to gasoline technology. This study revealed that class=SpellE>titania can indeed be used to convert syngas derived oxygenates to hydrocarbon at high temperature and pressure. Acetone condensation to mesitylene was studied very closely. The study revealed that the acid-base dual nature of class=SpellE>titania is key for the success of this reaction. When titaniawas combined with the zeolite H+/ZSM-5, a broad range of gasoline type hydrocarbon could be produced. Ethanol conversion to higher alcohols was studied as part of a partial deoxygenation of ethanol research. While this conversion was possible on class=GramE>titania, zirconia proved to be a better catalyst. Ethanol could be converted to 1-butanol and other higher alcohols at high temperature and pressure. The mechanism by which this occurs was studied as well.

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Biodiesel is an alternative fuel that can be produced from a variety of lipid feedstocks. It has a number of perceived advantages over conventional petroleum diesel and as a result world production of biodiesel has increased dramatically since the turn of the century. Amongst its reported disadvantages is a widely observed increase in emissions of oxides of nitrogen, or NOx. Several explanations have been proposed for this phenomenon; in reality it is likely to be due to a combination of factors. The interplay of multiple factors affecting NOx emissions means that the increase in NOx when fuelling on biodiesel is not consistent or ubiquitous, but is instead dependent upon operating conditions and the specifics of the fuels being compared. The work documented in this thesis explores the nature and causes of the change in NOx emissions associated with biodiesel. The intention was that, by adjusting operating conditions, and using a wide range of fuels, doped with additives to achieve an even broader range of combustion characteristics, the impact of important variables would be made clearer, making it possible to reduce the problem to its lowest common denominators. In early experiments it was found that NOx emissions from biodiesel tended to be lower than those of petrodiesel under conditions where combustion was relatively highly premixed, but higher under more conventional diesel conditions where diffusion combustion constituted a larger proportion of heat release. The main experimental set revealed a definite increase in NOx emissions when fuelling on biodiesel, for a fixed start of combustion and equivalent degree of premixing. The addition of an oxygenate to petrodiesel elicited comparable NOx emissions to biodiesel, as a function of fuel-bound oxygen content; the data implies that the like-for-like biodiesel NOx increase may be a direct result of fuelbound oxygen. However, the like-for-like biodiesel NOx increase varies dependent upon operating conditions. In part, this may be related to higher apparent heat release rate (AHRR) through the diffusion burn phase when fuelling on biodiesel. This may result from the extended biodiesel injection duration. Across operating conditions, the extent to which smoke emissions when fuelling on petrodiesel exceeded those when fuelling on biodiesel was generally correlated with the magnitude of the biodiesel NOx increase; where the difference in smoke emissions was small, the biodiesel NOx increase was small, and where the difference in smoke emissions was more substantial, so was the difference in NOx emissions. This suggests a possible connection to changes in mixture stoichiometry. When differentiating between fuels, increased cetane number reduces NOx, and increased oxygen content increases NOx. Biodiesel does not necessarily have higher NOx emissions than petrodiesel: the biodiesel NOx increase exists where the difference in cetane number is insuffi cient to counteract the effects of fuel-bound oxygen content.

In fire debris analysis, substrate contribution refers to compounds present within the material collected that can interfere with the instrumental detection of ignitable liquids or contribute petroleum or alcohol-based compounds, which may complicate the interpretation. The concept of substrate contribution was brought to light by "The petroleum-laced background" by Lentini et al. focusing on commercial products (e.g. tennis shoes, magazines, etc.), the publication successfully illustrated that these products can produce chromatograms similar to those generated by the presence of petroleum-based ignitable liquids (ILs). As a result, Lentini et al. demonstrated that fire debris analysts can identify the presence of ignitable liquids without realizing the compounds in question might be the result of the manufacturing processes, and are inherent to the substrate in question. Therefore, the findings may or may not be probative. Gasoline is easily accessible and is frequently used by arsonists. As such, fire debris analysis focuses primarily on petroleum-based compounds. However, oxygenated solvents, which encompass all oxygen-containing compounds as defined by the American Society for Testing and Materials (ASTM) classification scheme, can also be used in an arson event. Despite the potential to be used as ILs, little is known regarding the recovery of these compounds. Previous thesis projects from the Biomedical Forensic Sciences program at Boston University School of Medicine explored and optimized the use of zeolites in recovering low molecular weight oxygenated ignitable liquids. An isothermal gas chromatography/mass spectrometry (GC/MS) method was also developed to detect these oxygenated ILs. The results from these projects show that zeolites have the potential to be used in forensic casework. Inspired by previous publications and thesis research, the goal of this project was to first develop a reference library on substrate contribution from oxygenates (e.g. ethanol, isopropanol and acetone) present in commercial products using the isothermal GC/MS methods. The development of this reference library included a specific interest in wood treatment products, considering wood is one of the most commonly submitted fire debris materials. The second stage involved an attempt at evaluating extraction efficiencies of activated charcoal strip and zeolites. The results of this project suggested that automotive and food products examined contained only acetone and ethanol respectively, while the variety of oxygenates found in household and personal care products indicated further analysis of additional products in these categories would be beneficial. Moreover, the results also reaffirmed zeolites' role in recovering oxygenated ILs in a controlled testing environment using KimWipes as a non-contributing substrate. However, the instrumental method required some modifications, as there was partial separation between ethanol and acetone. The results from applying products onto wooden blocks suggested that activated charcoal strips recovered more oxygenates than zeolites. This unexpected result prompted an investigation into the existing extraction parameters. The investigation suggested that the wooden blocks themselves were responsible for the unexpected recovery results, and future studies would be needed to understand if this recovery was substrate-specific.

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The use of transition metal catalysts - either homogeneous (discrete well-defined metal complexes) or heterogeneous (more poorly-defined metal surfaces) - play an important role in the transformations of small substrates into larger, value-added compounds. Although heterogeneous catalysts have the greater industrial applicability, there has been enormous interest in homogeneous transition metal systems for effecting selective transformations of small substrate molecules. The bulk of these homogeneous systems are mononuclear. Perhaps surprisingly, very little research has focuses on systems with adjacent metal centres. Binuclear systems possess adjacent metals that may interact and possibly lead to transformations not observed in monometallic systems. It is this opportunity for adjacent metal involvement in substrate activation that is the focus of this dissertation. the goal of this research is to gain an increased understanding of metal-metal cooperativity and adjacent metal involvement in substrate transformations; how can adjacent metal involvement lead to substrate activation not seen in monometallic counterparts, and what role does each metal play in these interactions, particularly when the two metals are different. Throughout this dissertation examples of transformation unique to systems with at least two metals are presented and examined with a particular focus on the roles of the two metals and any associated binding modes in these transformations. In addition, by comparing the RhOs, RhRu and IrRu systems, the influence of metal substitution is also examined. For example, diazoalkane activation and C-c bond formation promoted by the Rh-based systems is investigated, the roles of the adjacent metals of the IrRu system in the conversion of methylene groups to oxygenates is examined, and the unusual geminal C-H bond activation of olefinic substrates is explored. Overall, the work presented within this thesis adds to the growing understanding of adjacent metal cooperativety, leading us toward a more rational approach to the design of homogeneous homo- and heterobimetallic catalysts, heterogeneous catalyst and nanoparticle catalysts for selective substrate transformations.

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