Tin-, zirconium- and hafnium-containing siliceous Beta zeolite were investigated in the Meerwein–Ponndorf–Verley reduction of furfural under continuous flow conditions.

An important advance in fluid surface control was the amphiphilic surfactant composed of coupled molecular structures (i.e., hydrophilic and hydrophobic) to reduce surface tension between two distinct fluid phases. However, implementation of simple surfactants has been hindered by the broad range of applications in water containing alkaline earth metals (i.e., hard water), which disrupt surfactant function and require extensive use of undesirable and expensive chelating additives. Here we show that sugar-derived furans can be linked with triglyceride-derived fatty acid chains via Friedel–Crafts acylation within single layer (SPP) zeolite catalysts. These alkylfuran surfactants independently suppress the effects of hard water while simultaneously permitting broad tunability of size, structure, and function, which can be optimized for superior capability for forming micelles and solubilizing in water.

Al, Ga, Fe, and B metal substituents have been examined for their ability to change the Brønsted acid strength of BEA zeolite and inhibit undesired hydrolysis in the production of aromatics from furan, 2-methylfuran, and 2,5-dimethylfuran. We employed electronic structure calculations to examine this series of furans in H-[Al]-, H-[Fe]-, H-[Ga]-, and H-[B]-BEA zeolites. These calculations were used to parametrize a microkinetic model to make direct comparisons to experiments run with furan and DMF in the weakest and strongest acid zeolites, H-[B]-BEA and H-[Al]-BEA, respectively. Electronic structure calculations revealed that the Diels−Alder reaction remains unaffected by changes to the Brønsted acid strength of the zeolite, whereas the dehydration and hydrolysis reactions are affected in a fashion reminiscent of general acid catalysis. Interestingly, despite its significantly lower acid strength, H-[B]-BEA was experimentally shown to have an activity similar to that of H-[Al]-BEA for the production of both benzene and p-xylene from furan and 2,5-dimethylfuran, respectively. Analysis with the microkinetic model revealed that, even with this weaker heterogeneous acid site, the dehydration reaction is sufficiently catalyzed, activating the aromatic production pathway. The use of a weaker, heterogeneous Brønsted-acidic zeolite did not have a significant effect on the product selectivity, however, indicating that the same reaction pathways are active with both catalysts.

No abstract

A four-step catalytic process was developed to produce p-methylstyrene from methylfuran, a biomass-derived species. First, methylfuran was acylated over zeolite H-Beta with acetic anhydride. Second, the acetyl group was reduced to an ethyl group with hydrogen over copper chromite. Third, p-ethyltoluene was formed through Diels-Alder cycloaddition and dehydration of 2-ethyl-5-methyl-furan with ethylene over zeolite H-Beta. Dehydrogenation of p-ethyltoluene to yield p-methylstyrene completes the synthesis but was not investigated because it is a known process. The first two steps were accomplished in high yield (>88 %) and the Diels-Alder step resulted in a 67 % yield of p-ethyltoluene with a 99.5 % selectivity to the para isomer (final yield of 53.5 %). The methodology was also used for the preparation of p-divinylbenzene. It is shown that acylation of furans over H-Beta zeolites is a highly selective and high-yield reaction that could be used to produce other valuable molecules from biomass-derived furans.

No abstract

2013iii ACKNOWLDGEMENTSThere are many people without whom this thesis would not have been possible. I must thank Ashish Mhadeshwar for the incredible amount of knowledge he imparted and the guidance he provided in order for this research to be conducted, shared at conferences and published. Many thanks to Doug Cooper, Bill Mustain and Ranjan Srivastava for standing in as advisors and providing support that was above and beyond expectations. I want to thank everyone that has become part of my UConn family, without whom this project would have been possible but much less fun:

Using vegetable oil based alternative fuels for diesel engines has grown in interest over recent years due to the rising cost of petroleum products and instability in the energy marketplace. One of the major hurdles to overcome in using vegetable oil as a diesel fuel is high viscosity. Here, we experimentally determine the viscosity of unaltered waste soybean oil (WSO) blended with petroleum fuels. Three blend viscosity models Arrhenius, Wright, and the ASTM D7152-05 Standard were evaluated for viscosity prediction accuracy over a temperature range of -10 to 40°C. Results indicated that the Arrhenius method using volume fractions was the most accurate predictor of viscosity for binary blends made of WSO and diesel (2.31% absolute average deviation) as well as multicomponent blends made from WSO, diesel, kerosene, and gasoline (8.72% absolute average deviation). An intermolecular interaction correction factor was empirically determined for each model in an effort to improve prediction accuracy for the multi-component blends. Using the correction constants improved the absolute average deviation for the Arrhenius method to 6.85%, 5.87% for the Wright method based on mass fractions, and 9.67% for the ASTM method based on mass fractions. The use of this correlation constant for the Arrhenius method was only helpful for blends containing more that 30% WSO, indicating that molecular interaction behavior only deviates significantly from ideality at these higher WSO fractions.