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Mechanistic Chemistry of TG Oil Cracking
Mentors: E. Kozliak and A. Kubatova (Chem) and W. Seames (ChE)

The triacyl glycerides (TGs) in bio-oils produced by oil seed crops, algae, and microbes can be processed into fuels by a number of pathways. Thermal (i.e., non-catalyzed) cracking in an oxygen-free environment is attractive because it models the natural conversion of TGs to petroleum, only conducted on a much shorter timescale. Recently, thermal TG cracking was shown to be a unique and surprisingly specific pathway leading to a well-defined mixture consisting mostly of linear saturated hydrocarbons and fatty acids of a specific homology pattern, as well as aromatic and other cyclic hydrocarbons [1]. This project is designed to gain insights into the chemistry of TG oil cracking, focusing on the mechanism of formation and structure of chemicals formed as by-products. Capitalizing on the use of analytical techniques developed in prior research [1, 2], reaction pathways will be evaluated using an on-line pyrolysis unit directly connected to a gas chromatograph with flame ionization and mass spectrometric detectors (GC-FID/MS). Evaluation will be based on quantification of the decay of initial compounds, e.g., pure individual TGs of varied chemical structure, combined with the identification and quantification of products. Insights into the specific mechanisms associated with TG cracking will be explored.

Graphite Furnace Atomic Absorption Spectrometer (GFAAS) Modeling of Trace Elements (TE) Atomization in Coal Combustion Furnaces
Mentors: E. Kozliak, D. Pierce (Chem) and W. Seames (ChE)

The physical property data necessary to model the vapor-melt partitioning of TEs (e.g. As, Se, Sb) in the presence of Si, Si-Al, and Fe matrices at localized combustion conditions at the micro-environmental conditions of the burning char particles are currently not available (temperatures >2400K, which creates insurmountable problems for accurate modeling). A robust and reliable method has been developed to determine the Arrhenius activation parameters for any target analyte, using a GFAAS as an extremely high-temperature in-situ burning char simulator/sample collector/analytical platform (all at the same time). This follow-on undergraduate project will focus on applying this method to TEs embedded in matrices, i.e., determining the activation parameters for TE atomization over Fe, Si, and Si-Al melts at 1900 to 2400 K. To model separately the matrix effects in the organic fraction of coal and inorganic inclusions, experiments will be conducted with and without carbon (using plain and W- and Ta-coated AA furnace).

Photovoltaic Cell Manufacture to Explore Ru(II) and Re(I)-Terpyridines
Mentors: Sean E. Hightower (Chem) and Edward Kolodka (ChE)

Recent research in our laboratory has shown that the oxidation potential of Re(I)-terpyridines occurs at potentials near those of commonly used redox mediators such as the iodide/triiodide couple. Furthermore, these complexes absorb light throughout the entire visible spectrum. These data suggest higher efficiencies can be achieved using these systems. In this project, the REU student will prepare photovoltaic devices based on either Ru(II) or Re(I)-terpyridines - none of which have been previously prepared. Studies will also include the investigation of different redox mediators.

Particulate Emissions from Coal-Biomass Combustion
Mentors: Steve Benson (ChE), Frank Bowman (ChE)

Combustion of biomass together with coal has the potential to reduce the carbon footprint of coal-fired electricity generation. The chemical composition of biomass used can influence the composition and size distribution of fly ash particles produced during coal combustion, leading to changes in particulate and trace element emissions to the atmosphere. In this project, the REU student will help run experiments with a downflow combustor fed by a mixture of biomass and coal. Aerosol samples from the exhaust gas will be collected and analyzed to determine elemental composition and size distributions.

Development and Testing of Membrane Electrode Assemblies (MEA) Using UND-Developed Silica-Based Nanocatalysts
Mentors: Michael Mann (ChE), Julia Zhao (Chem)

The REU student will determine optimal fabrication conditions for MEAs using both carbon-based catalysts (baseline) and UND produced silica-based MEAs. Factors to be investigated include solvent type, hot pressing conditions, and cathode and anode catalyst loading. The student will also participate in testing generating data to quantify electrical performance as characterized by fuel cell losses, fuel crossover, and catalyst poisoning as a function of time.

Atmospheric Aerosol Formation from Renewable Biofuels
Mentors: Frank Bowman (ChE) and Alena Kubatova (Chem)

Biofuels are a promising replacement for existing transportation fuels because they can significantly reduce net carbon emissions. However their other atmospheric emissions have not yet been fully characterized. A new laboratory aerosol chamber will be used to investigate particulate matter formation reactions arising from biofuel combustion emissions. The system consists of a 20 m3 Teflon reaction chamber within a temperature controlled enclosure surrounded by UV lights to mimic solar radiation. Gas and particle emissions from biofuel combustion are added into the chamber and gas reactions, particle growth, and dilution and depositional losses are monitored by a variety of gas and particulate instrumentation. In this project, the REU student will help with chamber characterization experiments to determine particle deposition rates, photochemical reaction rates, and instrument responses, followed by a series of experiments exploring the formation of secondary aerosol formation from different biofuels.

Computational Chemistry Research in Coal and Biomass Combustion
Mentor: Dr. Mark Hoffmann (Chem)

This project explores the quantum mechanical descriptions of the electronic structures of molecules and reactions of relevance to the understanding of combustion processes. Our primary focus is on chemical reactions that are difficult or impossible to measure accurately in the laboratory, so that the computational results are critical to developing a correct understanding of the chemical systems. We are able and interested in examining reactions that involve excited electronic surfaces, as a result of thermal or photochemical processes. We are particularly interested in reactions that involve O2, O3, and oxides of nitrogen with reactive molecules in the upper atmosphere and in coal combustors. Recent work has extended our capabilities in describing gas-phase reactions to reactions occurring on clusters that mimic surfaces. The student will develop familiarity with the use and theoretical underpinnings of well-established main techniques of modern quantum chemistry (e.g., Hartree-Fock (HF) method, hybrid density functional methods such as B3LYP, and second-order Møller-Plesset perturbation theory), as well as novel multireference perturbation theory approaches developed at UND, in the context of a combustion-relevant chemical problem. The results to be obtained will be matched with the experimental results obtained by chemists (Kozliak) and ChEs (Seames).

Scanning Tunneling Microscopy Study on Self-Assembled Monolayers of Porphyrin Molecules on Highly Oriented Pyrolytic Graphite for Solar Cells
Mentor: Nuri Oncel (Physics)

Thin films of molecules with certain physical and chemical properties have been implemented in various electronic and optoelectronic devices such as electroluminescent devices, sensors, diodes, and photovoltaic cells. High quality molecular films and interfaces can be realized with the help of self-assembly. Molecular self-assembly is due to the mutual interactions between the molecules ranging from weak and non-directional van der Waals bonds to strong and directional hydrogen bonds. Porphyrins have a nearly square core conformation, with a two-dimensional (2D) delocalized conjugated p-electron system. The REU student will study the physical properties of thin films of porphyrin molecules adsorbed on HOPG at solid liquid interfaces using a scanning tunneling microscope. We are particularly interested in controlling surface morphology of a porphyrin film by co-adsorbing them with chain-like molecules.

Uncertainty Quantification and Optimization in Modeling Advanced Combustion Systems
Mentor: Gautham Krishnamoorthy (ChE)

High fidelity computational models of the flows within emerging power generation system devices, such as gasifiers, carbon capture systems, and oxy-fuel combustors, can yield valuable insights into their design, operation and optimization. Modern computational power enables us to model these devices at resolutions and accuracies not possible previously. However, in any modeling exercise we need to achieve a useful trade-off between computational speed and accuracy. We also need to be able to predict the variations in output subject to uncertainties and variations in the fuel, flow rates, boundary conditions and material properties. The goal of this project is to examine a range of physical models for multi-phase flows encountered in oxy-fuel combustion and coal/biomass gasifiers that vary in their computational speeds and accuracies. Next, the inherent errors and uncertainties encountered when employing them will be quantified to enable us to undertake model refinements or select the "optimum" models among existing ones to accurately simulate gasifiers or oxy-combustors within a reasonable time.

The Four-Electron Reduction of Carbon Dioxide (CO2)
Mentor: Sean E. Hightower (Chem)

Polypyridine complexes of d6 metals such as Ru(II), Os(II), and Re(I) have received a great deal of attention because they can act as electrocatalysts and photocatalysts for the reduction of carbon dioxide (CO2) to formate (O2CH–) and carbon monoxide (CO). Although these reactions have been significant in determining the efficacy of these systems in the reduction of CO2, they only proceed by way of a two-electron reduction. This is a significant drawback when considering that the complete sequence for the reduction of CO2 to methanol (CH3OH), for example, requires an overall six-electron reduction. In this project, the REU student will design and prepare catalytic systems capable of proceeding past the two-electron stage.

Functionalization of Aliphatic and Aromatic C-H Bonds Using Pd(II) for Renewable Chemical Production
Mentor: Irina Smoliakova (Chem)

Catalytic functionalization of C-H bonds is the most atom- and energy-efficient method for preparation of fine chemicals. The ultimate goal of our studies is to use catalytic transformations for synthesis of novel types of compounds, which could be employed as catalysts in new catalytic processes, essential for sustainable production of chemicals from non-petroleum sources. Members of our group study regioselective functionalization of C-H bonds in aryl and alkyl groups using the two-step approach: C-H activation of appropriate heteroatom-containing substrates by stoichiometric or catalytic amounts of a Pd(II) species followed by reaction of the formed metalated species with metal phosphides or secondary phosphines. The products of the proposed reaction sequence are aminophosphines and related hemilabile ligands, which are highly efficient catalysts in a number of asymmetric transformations.

Pretreatment and Enzymatic Hydrolysis of Forage Sorghum as a Renewable Source for Biofuels and Green Chemicals
Mentor: Yun Ji (ChE)

The development and conversion of sustainably produced biomass as a feedstock for biorefineries, biofuels, bioproducts and bioenergy is a critical priority due to concerns in achieving energy security, environmental and human health, rural economic development, and the need to diversify products and markets for the forest and agricultural industries. The objective of the proposed project is to evaluate and optimize the biofuel production from forage sorghum as a non-food resource and thus improve the local economy and reduce the dependence of our nation on foreign sources of energy. This project is divided into two tasks (pretreatment and enzymatic hydrolysis) to evaluate the forage sorghum as a potential biofuel feedstock. This project is appropriate for an undergraduate student interested in bioenergy research. The student will obtain hands-on experience in using a steam-jacketed biomass pretreatment reactor, an incubator shaker for enzymatic hydrolysis and instruments such as High Performance Liquid Chromatography (HPLC) and UV for analytical measurements.

Stereospecific Membranes
Mentor: Ed Kolodka (ChE) and Brian Tande (Che)

This goal of this project is to develop membranes which can be used to separate specific enantiomers from racemic mixtures. Potential applications include drug purification and fine chemical synthesis. These membranes will be synthesized from chiral dendrimers (highly branched polymers). The physical characteristics and permeability of the membranes will be determined.