In this work, SCWG of glucose, cellulose and pinewood was studied at different operating conditions with and without catalyst. Three parameters studied included temperature (400, 470, 500 and 550oC), water to biomass weight ratio (3:1 and 7:1) and catalyst (Ni/MgO, Ni/activated carbon, Ni/Al2O3, Ni/CeO2/Al2O3, dolomite, NaOH, KOH, activated carbon and olivine), which were varied for gasification of glucose, cellulose and pinewood. By comparing the results from model compound (glucose and cellulose) with that from real biomass (pinewood), the mechanism of how the individual compounds are gasified was explored. For catalytic runs with glucose, NaOH had the best activity for improving H2 formation. H2 yield increased by 135% using NaOH compared to that for run without catalyst at 500oC with a water to biomass weight ratio of 3:1. At the same operating conditions, the presence of Ni/activated carbon (Ni/AC) contributed to an 81% increase in H2 yield, followed by 62% with Ni/MgO, 60% with Ni/CeO2/Al2O3 and 52% with Ni/Al2O3. For catalytic runs with cellulose, the H2 yield increased by 194% with KOH compared to that for run without catalyst at 400oC with a water to biomass ratio of 3:1. At the same operating conditions, the presence of Ni/CeO2/Al2O3 contributed to a 31% increase in H2 yield followed by a 28% increase with dolomite. When the water to biomass ratio was increased from 3:1 to 7:1, H2 yield from glucose gasification was increased by 40% and 33% at 400 and 500oC, respectively, and the H2 yield of cellulose gasification was increased by 44%, 11% and 22% at 400, 470 and 550oC, respectively. The higher heating value of the oil products derived from SCWG of both glucose and cellulose incresed in the presence of catalysts. As real biomass, pinewood was gasified in supercritical water at the suitable operation conditions (550oC with water to biomass ratio of 7:1) obtained from previous experiments, using three kinds of catalyst: Ni/CeO2/Al2O3, dolomite and KOH. At the same operating conditions, the gasification of pinewood had smaller yields of H2 (20 to 41%) compared with that from cellulose. The effect of the catalyst on H2 production from SCW in the absence of biomass was studied. The results showed that a trace amount of H2 was formed with Ni based catalyst/dolomite only while some CO2 was formed with Ni/AC. Most of the runs presented in this report were repeated once, some of the runs had been triplicated, and the deviation of all results was in the range of ±5%.

The direct catalytic hydrogenation of nitrile butadiene rubber (NBR) in latex form was studied as a model system for the development of a new latex hydrogenation process for the modification of unsaturated diene-based polymers. NBR is a synthetic rubber of copolymerized acrylonitrile and butadiene produced in latex form by emulsion polymerization. The catalytic hydrogenation of NBR is an important post-polymerization process resulting in a more stable and tougher derivative, hydrogenated NBR (HNBR), which has been widely used in the automotive and oil drilling industry. The present commercial process involves a number of cumbersome steps to obtain solid NBR from the latex and subsequent dissolution of the solid NBR in a large amount of organic solvent followed by solvent recovery after coagulation of the hydrogenated NBR. Since NBR is produced in latex form, it is very desirable to directly hydrogenate NBR in the latex form which will significantly simplify the hydrogenation process and facilitate subsequent applications. As an economical and environmentally benign alternative to the commercial processes based on the hydrogenation of NBR in organic solution, this direct latex hydrogenation process is of special interest to industry. The objective of this project is to develop an efficient catalytic system in order to realize the direct catalytic hydrogenation of NBR in latex form. OsHCl(CO)(O2)(PCy3)2 was initially used as the catalyst to investigate the possibility of hydrogenation of NBR in latex form and to understand the major factors which affect the hydrogenation operation. It was found that an organic solvent which is capable of dissolving or swelling the NBR was needed in a very small amount for the latex hydrogenation using the Os catalyst, and gel occurred in such a catalytic system during hydrogenation. Wilkinson’s catalyst, RhCl(PPh3)3, was then used for the latex hydrogenation in the presence of a small amount of solvent successfully without gel formation. Further investigation found that Wilkinson’s catalyst has a high activity for NBR latex hydrogenation without the use of any organic solvent. The influences of various operation conditions on hydrogenation rate, such as catalyst and polymer concentrations, latex system composition, agitation, reaction temperature and hydrogen pressure, have been investigated. It was found that the addition of triphenylphosphine (TPP) has a critical effect for the hydrogenation of NBR latex, and the hydrogenation rate was mainly controlled by the amount of catalyst which diffused into the polymer particles. In the presence of TPP, NBR latex can be hydrogenated to more than 95% degree of hydrogenation after about 30 hours at 160oC using Wilkinson’s catalyst with a catalyst to NBR rubber ratio of 1 wt%, without the addition of any organic solvent. The apparent activation energy for such NBR latex hydrogenation over the temperature range of 152oC to 170oC was found to be 57.0 kJ/mol. In the present study, it was also found that there are some impurities within the NBR latex which are detrimental to the hydrogenation reaction and are suspected to be water-soluble surfactant molecules. Deliberately designed solution hydrogenation experiments were conducted to study the impurity issue, and proper latex treatment methods have been found to purify the latex before hydrogenation. To improve the hydrogenation rate and to optimize the latex hydrogenation system, water soluble RhCl(TPPMS)3 catalyst (TPPMS: monosulphonated-triphenylphosphine) was used for the latex hydrogenation of NBR. The latex hydrogenation using the water soluble catalyst with TPP can achieve more than 90% degree of hydrogenation within 20 hours at 160oC. Further experiments using RhCl3 with TPP proved that the water soluble RhCl3 can be directly used as a catalyst precursor to generate the catalytic species in situ for the latex hydrogenation, and a stable NBR latex with 96% degree of hydrogenation can be produced without any gel problem within 19 hours of reaction at 160oC. The catalyst mass transport processes for these Rh based catalysts in the latex system were investigated in order to further optimize the solvent-free latex hydrogenation process. While maintaining the emulsified state of the original latex, the direct catalytic hydrogenation of NBR latex can be carried out efficiently without any cross-linking problem to more than 92% degree of hydrogenation within 8 hours at 160oC. As a result of this research project, new latex hydrogenation technologies were successfully developed to fulfill all major requirements for a solvent-free polymer latex hydrogenation route, which is a significant milestone for the improvement of this polymer modification technology. The finding of TPP’s role as the “catalyst mass transfer promoter” is a breakthrough for the research field related to the hydrogenation of unsaturated diene-based polymers in latex form.

The direct catalytic hydrogenation of nitrile butadiene rubber (NBR) in latex form was studied as a model system for the development of a new latex hydrogenation process for the modification of unsaturated diene-based polymers. NBR is a synthetic rubber of copolymerized acrylonitrile and butadiene produced in latex form by emulsion polymerization. The catalytic hydrogenation of NBR is an important post-polymerization process resulting in a more stable and tougher derivative, hydrogenated NBR (HNBR), which has been widely used in the automotive and oil drilling industry. The present commercial process involves a number of cumbersome steps to obtain solid NBR from the latex and subsequent dissolution of the solid NBR in a large amount of organic solvent followed by solvent recovery after coagulation of the hydrogenated NBR. Since NBR is produced in latex form, it is very desirable to directly hydrogenate NBR in the latex form which will significantly simplify the hydrogenation process and facilitate subsequent applications. As an economical and environmentally benign alternative to the commercial processes based on the hydrogenation of NBR in organic solution, this direct latex hydrogenation process is of special interest to industry. The objective of this project is to develop an efficient catalytic system in order to realize the direct catalytic hydrogenation of NBR in latex form. OsHCl(CO)(O2)(PCy3)2 was initially used as the catalyst to investigate the possibility of hydrogenation of NBR in latex form and to understand the major factors which affect the hydrogenation operation. It was found that an organic solvent which is capable of dissolving or swelling the NBR was needed in a very small amount for the latex hydrogenation using the Os catalyst, and gel occurred in such a catalytic system during hydrogenation. Wilkinson’s catalyst, RhCl(PPh3)3, was then used for the latex hydrogenation in the presence of a small amount of solvent successfully without gel formation. Further investigation found that Wilkinson’s catalyst has a high activity for NBR latex hydrogenation without the use of any organic solvent. The influences of various operation conditions on hydrogenation rate, such as catalyst and polymer concentrations, latex system composition, agitation, reaction temperature and hydrogen pressure, have been investigated. It was found that the addition of triphenylphosphine (TPP) has a critical effect for the hydrogenation of NBR latex, and the hydrogenation rate was mainly controlled by the amount of catalyst which diffused into the polymer particles. In the presence of TPP, NBR latex can be hydrogenated to more than 95% degree of hydrogenation after about 30 hours at 160oC using Wilkinson’s catalyst with a catalyst to NBR rubber ratio of 1 wt%, without the addition of any organic solvent. The apparent activation energy for such NBR latex hydrogenation over the temperature range of 152oC to 170oC was found to be 57.0 kJ/mol. In the present study, it was also found that there are some impurities within the NBR latex which are detrimental to the hydrogenation reaction and are suspected to be water-soluble surfactant molecules. Deliberately designed solution hydrogenation experiments were conducted to study the impurity issue, and proper latex treatment methods have been found to purify the latex before hydrogenation. To improve the hydrogenation rate and to optimize the latex hydrogenation system, water soluble RhCl(TPPMS)3 catalyst (TPPMS: monosulphonated-triphenylphosphine) was used for the latex hydrogenation of NBR. The latex hydrogenation using the water soluble catalyst with TPP can achieve more than 90% degree of hydrogenation within 20 hours at 160oC. Further experiments using RhCl3 with TPP proved that the water soluble RhCl3 can be directly used as a catalyst precursor to generate the catalytic species in situ for the latex hydrogenation, and a stable NBR latex with 96% degree of hydrogenation can be produced without any gel problem within 19 hours of reaction at 160oC. The catalyst mass transport processes for these Rh based catalysts in the latex system were investigated in order to further optimize the solvent-free latex hydrogenation process. While maintaining the emulsified state of the original latex, the direct catalytic hydrogenation of NBR latex can be carried out efficiently without any cross-linking problem to more than 92% degree of hydrogenation within 8 hours at 160oC. As a result of this research project, new latex hydrogenation technologies were successfully developed to fulfill all major requirements for a solvent-free polymer latex hydrogenation route, which is a significant milestone for the improvement of this polymer modification technology. The finding of TPP’s role as the “catalyst mass transfer promoter” is a breakthrough for the research field related to the hydrogenation of unsaturated diene-based polymers in latex form.

There has been a growing interest in using lean-burn engines due to their higher fuel economy and associated lower CO2 emissions. However, there are challenges in reducing NOX in an O2-rich (lean-burn) exhaust, and in low temperature soot oxidation. NOX storage/reduction (NSR) and selective catalytic reduction (SCR) are commercial NOX reduction technologies, and both are more efficient with levels of NO2 that are higher than those that are in engine exhaust (engine-out NO2 levels are ~10% of the total NOX). Therefore diesel oxidation catalysts are installed upstream of these technologies to provide NO2 through NO oxidation. The motivation behind this research project was two-fold. The first was to gain a better understanding of the effect of hydrocarbons on NO oxidation over a monolithic diesel oxidation catalyst. The second was to spatially resolve competitive oxidation reactions as a function of temperature and position within the same diesel oxidation catalyst (as that used in the first part). A technique known as spatially resolved capillary-inlet mass spectrometry (SpaciMS) was used to measure the gas concentrations at various positions within the catalyst. Diesel engine exhaust contains a mixture of compounds including NO, CO and various hydrocarbons, which react simultaneously over a catalyst, and each can influence the oxidation rates of the others. While studying the effect of hydrocarbons on NO oxidation in this project, propylene was found to have an apparent inhibition effect on NO oxidation, which increased with increasing propylene concentration. This apparent inhibition is a result of the NO2, as a product of NO oxidation, reacting with the propylene as an oxidant. Experiments with NO2 demonstrate a significant temperature decrease in the onset of NO2 reduction when propylene was present, which decreased further with increasing amounts of propylene, verifying NO2 as an oxidant. Similar results were observed with m-xylene and dodecane addition as well. The results also demonstrate that NO2 was consumed preferentially relative to O2 during hydrocarbon oxidation. With low inlet levels of O2, it was evident that the addition of NO2 had an apparent inhibition effect on propylene oxidation after the onset of NO2 reduction. This subsequent inhibition was due to the NO formed, demonstrating that C3H6 results in reduced NO2 outlet levels while NO inhibits C3H6 oxidation. The development of new models as well as validation of existing models requires the ability to spatially resolve oxidation reactions within a monolith. Spatially-resolved data will also give catalyst manufacturers insight into the location of active fronts, thereby directing the design of more efficient catalysts. In this research project, spatially resolving the oxidation reactions demonstrated that H2 and CO are oxidized prior to C3H6 and C12H26 and clearly show back-to-front ignition of the reductant species. An enhancement in NO oxidation was observed at the same time as dodecane oxidation light off, likely related to dodecane partial oxidation products.

Lean burn engines are more fuel efficient than standard stoichiometric-burn engines but at the same time, the conventional three-way catalyst is not effective in reducing the NOx in oxygen-rich exhaust. One of the recent advancements in exhaust after treatment technologies for lean burn engines is the NOx storage and reduction (NSR) methodology. In this mechanism, NOx is stored on the storage component of a NSR catalyst during normal engine operation. However, before the catalyst reaches its saturation capacity, an excess of fuel is injected to the engine for a very short period resulting in reductant rich exhaust and during this period, NOx is released and subsequently reduced to N2, therefore, restoring the storage capacity of the catalyst. The operation is cyclic in nature, with the engine operating between an oxygen rich feed for long periods and a fuel rich feed for relatively shorter periods. To implement this technology in the most efficient way, a detailed understanding of the NSR chemistry under different operating conditions is required. For the past few years, several authors have studied the NSR systems using both experimental and modeling techniques. However, most of the models proposed in the literature were calibrated against the steady cyclic operation where the NOx profiles are similar for each cycle. In real life situations, the engine operation changes with different driving conditions, occurring due to sudden acceleration, roads in hilly areas, non-uniform braking, etc., which results in operation with a number of different transient cycle-to-cycle regimes depending upon the frequency with which the engine operation is altered. Due to such varying conditions, it is very important to investigate the significance of transients observed between the two different steady cycle-to-cycle operations for the optimization and control purposes. Also, the models in the literature are specific to the catalyst used in the study and therefore, their adaptation to other NSR catalysts is not straightforward. Therefore, one of the main motivations behind this research work is to develop a general approach to explain the storage dynamics. Moreover, the existing models have not studied the regeneration mechanisms, which is very important to explain the cyclic data in complete operation including both transients and steady state cycles. In this study, a pseudo one-dimensional model of a commercial NOx storage/release (NSR) catalyst is presented. The NOx storage is considered to be mass transfer limited, where as the storage proceeds, the barium carbonate particle is converted into the nitrate and for further storage, the NOx has to diffuse through this growing nitrate layer and a after certain depth, this penetration becomes nearly impossible. To explain the transient nature of the cyclic NOx profile, it is hypothesized that when incomplete regeneration occurs, only part of the nitrate is converted back to carbonate. Therefore, the nitrate layer increases in thickness with each cycle, thus making further storage increasingly more difficult. The shrinking core concept with incomplete storage in the lean phase followed by incomplete regeneration of the nitrate layer during the regeneration phase accounts for a net drop in storage capacity of the catalyst in each cycle, which continues decreasing until the amount of sites regenerated equal the amount used in NOx storage. The number of unknown parameters used for fitting were reduced by parameter sensitivity analysis and then fitted against a NOx profile at the reactor exit. The overall amount of NOx that can be stored in the lean phase of the cycle depends on the extent of regeneration that can be achieved during the previous rich phase, which in turn depends directly on the concentration of reductants in the feed. Therefore, there is a trade-off between the amount of fuel used and the NOx emissions. The proposed model can be potentially used to improve this trade-off by using model-based optimization techniques.

Samples of SCR catalysts were impregnated with the following alkali salts; KCl, K2SO4 and ZnCl2 at two different concentrations in a wet impregnation method. The activities of the six samples were measured in a test reactor and at different temperatures between 250-350 ºC. Compared to fresh catalyst, the impregnated samples all had lower activity. It seems like KCl is the most poisoning salt, depending on the lowest value of the activity. The experimental results are expected as compared to earlier articles, which reports that all alkali salts has deactivating effects on a catalyst and that KCl is among the most poisoning ones. By making a cross-section SEM analysis, the penetration of the metals at different depths in to the catalyst material wall was evaluated. An ICP-AES analysis was carried out in order to see the concentration of K and Zn of the test samples. Finally, the pore diameter and active surface was measured by BET method. Since the values of the active surface didn’t change compared to a fresh catalyst and the pore diameter was only slightly decreased we can suppose that the alkali salts deactivates the catalyst by coating of the catalyst pore structure and not as a pore blocking.

There has been a growing interest in using lean-burn engines due to their higher fuel economy and associated lower CO2 emissions. However, there are challenges in reducing NOX in an O2-rich (lean-burn) exhaust, and in low temperature soot oxidation. NOX storage/reduction (NSR) and selective catalytic reduction (SCR) are commercial NOX reduction technologies, and both are more efficient with levels of NO2 that are higher than those that are in engine exhaust (engine-out NO2 levels are ~10% of the total NOX). Therefore diesel oxidation catalysts are installed upstream of these technologies to provide NO2 through NO oxidation. The motivation behind this research project was two-fold. The first was to gain a better understanding of the effect of hydrocarbons on NO oxidation over a monolithic diesel oxidation catalyst. The second was to spatially resolve competitive oxidation reactions as a function of temperature and position within the same diesel oxidation catalyst (as that used in the first part). A technique known as spatially resolved capillary-inlet mass spectrometry (SpaciMS) was used to measure the gas concentrations at various positions within the catalyst. Diesel engine exhaust contains a mixture of compounds including NO, CO and various hydrocarbons, which react simultaneously over a catalyst, and each can influence the oxidation rates of the others. While studying the effect of hydrocarbons on NO oxidation in this project, propylene was found to have an apparent inhibition effect on NO oxidation, which increased with increasing propylene concentration. This apparent inhibition is a result of the NO2, as a product of NO oxidation, reacting with the propylene as an oxidant. Experiments with NO2 demonstrate a significant temperature decrease in the onset of NO2 reduction when propylene was present, which decreased further with increasing amounts of propylene, verifying NO2 as an oxidant. Similar results were observed with m-xylene and dodecane addition as well. The results also demonstrate that NO2 was consumed preferentially relative to O2 during hydrocarbon oxidation. With low inlet levels of O2, it was evident that the addition of NO2 had an apparent inhibition effect on propylene oxidation after the onset of NO2 reduction. This subsequent inhibition was due to the NO formed, demonstrating that C3H6 results in reduced NO2 outlet levels while NO inhibits C3H6 oxidation. The development of new models as well as validation of existing models requires the ability to spatially resolve oxidation reactions within a monolith. Spatially-resolved data will also give catalyst manufacturers insight into the location of active fronts, thereby directing the design of more efficient catalysts. In this research project, spatially resolving the oxidation reactions demonstrated that H2 and CO are oxidized prior to C3H6 and C12H26 and clearly show back-to-front ignition of the reductant species. An enhancement in NO oxidation was observed at the same time as dodecane oxidation light off, likely related to dodecane partial oxidation products.

Lean burn engines are more fuel efficient than standard stoichiometric-burn engines but at the same time, the conventional three-way catalyst is not effective in reducing the NOx in oxygen-rich exhaust. One of the recent advancements in exhaust after treatment technologies for lean burn engines is the NOx storage and reduction (NSR) methodology. In this mechanism, NOx is stored on the storage component of a NSR catalyst during normal engine operation. However, before the catalyst reaches its saturation capacity, an excess of fuel is injected to the engine for a very short period resulting in reductant rich exhaust and during this period, NOx is released and subsequently reduced to N2, therefore, restoring the storage capacity of the catalyst. The operation is cyclic in nature, with the engine operating between an oxygen rich feed for long periods and a fuel rich feed for relatively shorter periods. To implement this technology in the most efficient way, a detailed understanding of the NSR chemistry under different operating conditions is required. For the past few years, several authors have studied the NSR systems using both experimental and modeling techniques. However, most of the models proposed in the literature were calibrated against the steady cyclic operation where the NOx profiles are similar for each cycle. In real life situations, the engine operation changes with different driving conditions, occurring due to sudden acceleration, roads in hilly areas, non-uniform braking, etc., which results in operation with a number of different transient cycle-to-cycle regimes depending upon the frequency with which the engine operation is altered. Due to such varying conditions, it is very important to investigate the significance of transients observed between the two different steady cycle-to-cycle operations for the optimization and control purposes. Also, the models in the literature are specific to the catalyst used in the study and therefore, their adaptation to other NSR catalysts is not straightforward. Therefore, one of the main motivations behind this research work is to develop a general approach to explain the storage dynamics. Moreover, the existing models have not studied the regeneration mechanisms, which is very important to explain the cyclic data in complete operation including both transients and steady state cycles. In this study, a pseudo one-dimensional model of a commercial NOx storage/release (NSR) catalyst is presented. The NOx storage is considered to be mass transfer limited, where as the storage proceeds, the barium carbonate particle is converted into the nitrate and for further storage, the NOx has to diffuse through this growing nitrate layer and a after certain depth, this penetration becomes nearly impossible. To explain the transient nature of the cyclic NOx profile, it is hypothesized that when incomplete regeneration occurs, only part of the nitrate is converted back to carbonate. Therefore, the nitrate layer increases in thickness with each cycle, thus making further storage increasingly more difficult. The shrinking core concept with incomplete storage in the lean phase followed by incomplete regeneration of the nitrate layer during the regeneration phase accounts for a net drop in storage capacity of the catalyst in each cycle, which continues decreasing until the amount of sites regenerated equal the amount used in NOx storage. The number of unknown parameters used for fitting were reduced by parameter sensitivity analysis and then fitted against a NOx profile at the reactor exit. The overall amount of NOx that can be stored in the lean phase of the cycle depends on the extent of regeneration that can be achieved during the previous rich phase, which in turn depends directly on the concentration of reductants in the feed. Therefore, there is a trade-off between the amount of fuel used and the NOx emissions. The proposed model can be potentially used to improve this trade-off by using model-based optimization techniques.

The pore diameter of a catalyst support controls the diffusion of reactant molecules to the catalytic active sites; thus, affecting the rates and conversions of the hydrotreating reactions. Desirable textural properties of SBA-15 makes it a potential alternative to the conventionally used γ-Al2O3 support due to the fact that its pore size can be manipulated via controlling the synthesis parameters, while maintaining relatively high surface area. Larger pore diameter SBA-15 supports may facilitate the diffusion of bulky molecules as that of the asphaltenes present in the heavy petroleum fractions, making it a potential catalyst support for hydrotreating operations. Considering the very sour nature of Canadas bitumen with high sulfur contents in the range of 2-6 wt %, the appreciably high sulfur contents particularly present in Athabasca derived heavy gas oils (about 4 wt % sulfur), the rising demand for cleaner fuels, and also the increasing stringency on environmental standards, the need for novel and improved hydrotreating catalysts cannot be overemphasized. By varying the molar ratio of hexane to ammonium fluoride, the pore channels of SBA-15 could be varied. Controlling the pore diameter of these supports via micelle swelling facilitated the production of larger pore diameter SBA-15-supported catalysts. In this project, four mesoporous silica SBA-15 catalyst supports with pore diameters in the range of 5-20 nm were synthesized in the preliminary phase using hexane as the micelle swelling agent and subsequently utilized for the loading of 2 wt.% Fe and 15 wt.% W catalyst metals, respectively. The hexagonal mesoscopic structure of these materials were characterized using powder small-angle X-ray scattering (SAXS), N2 adsorption-desorption isotherms, TEM and SEM images. Powder XRD analysis evidenced inhomogeneous metal dispersion on the largest pore diameter catalyst. An optimum pore diameter of 10 nm was found for Cat-B and subsequently used to obtain the optimum Fe and W loadings required to achieve the best hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activities. The optimum catalyst was found to be Cat-H with metal loadings of 3 wt.% Fe and 30 wt.% W. At these loadings and temperatures of 375°C, 388°C, and 400°C, HDS activities of 53.4%, 64.1%, and 73.3% with corresponding HDN activities of 21.9%, 26.2%, and 38.3%, respectively, were recorded. Catalytic performance evaluations conducted on equal mass loading using a reference commercial γ-Al2O3-supported FeW catalyst offered HDS activities of 69.3%, 80.4%, and 89.1%, with corresponding HDN activities of 16.4%, 32.4%, and 49.3% at the same temperatures studied. However, no significant changes in HDS and HDN activities were observed for similar evaluations on volume percent metals loading basis. Kinetic studies performed with the optimum FeW/SBA-15 catalyst suggested activation energies of 147.2 and 150.6 kJ/mol for HDS and HDN, respectively, by the Langmuir-Hinshelwoods model. Similar results were predicted by the Power Law and Multi-parameter models for HDS (129.6 and 126.7 kJ/mol, respectively), which does not conclusively make the latter model clearly stand out as the best. Data fitting by the Power Law suggested reaction orders of 2 and 1.5 for HDS and HDN, which seem to be consistent for the hydrotreatment of heavy gas oil. Finally, a long-term deactivation study spanning a period of 60 days time-on-stream showed the optimum catalyst to be stable under hydrotreating experiments conducted in a downward flow micro-trickle bed reactor at temperature, pressure, liquid hourly space velocity (LHSV), and gas/oil ratio of 375400˚C, 8.8 MPa, 1h-1, and 600 mL/mL (at STP), respectively.

The major goals of this work were to: develop a new methodology for the preparation of site-isolated catalytic sites on a silica surface, prepare the first truly single-site supported metallocene/CGC polymerization catalyst, and develop structure-reactivity relationships for these new systems. To synthesize these novel catalysts, the approach taken was to develop a protocol which allows for the synthesis of an aminosilica material with isolated, uniform amine sites. This patterned aminosilica was then used as a scaffold to support a constrained geometry catalyst. These functionalizations occurred at essentially a quantitative level, in stark contrast to previous literature reports. The patterned catalysts were evaluated in the polymerization of ethylene and compared to densely loaded literature materials. Overall, it was found the patterned materials were 5-10 times more active than traditional immobilized CGC catalysts. The patterned catalysts were also found to be effective catalysts for the copolymerization of norbornenes (including functionalized norbornenes) and ethylene, the first reported use of a tethered CGC for the production of ethylene-norbornene copolymers. The control materials were inactive in these polymerizations, providing further evidence that the patterning protocol allows for the synthesis of unique highly active, isolated catalytic sites. Various structural components of the immobilized CGC developed in this work were tested for their impact on catalyst synthesis and reactivity in ethylene polymerizations. The results showed the patterned materials in general behaved according to the trends seen in homogeneous CGC polymerizations. These results, while congruent with similar homogeneous CGC studies, are in direct conflict with previous work on supported CGCs reported in the literature. This discrepancy is likely the result of the difference between the isolated, possibly single-site patterned catalysts developed in the course of this work and the multi-sited catalysts prepared by traditional supporting protocols. This also further illustrates the difficulty in developing structure-reactivity relationships when ill-defined solid catalysts are used.