Doctor of Philosophy, The Ohio State University, 2013, Materials Science and Engineering

Carbon steel is susceptible to the liquid-air interface (LAI) corrosion in liquid nuclear waste and in simulants, but a precise understanding of the mechanism is still missing. This work aimed to expand the understanding of the LAI corrosion mechanism. LAI corrosion was found to initiate at the very top of the meniscus in the form of pits under potentiostatic polarization condition. Gas bubbles were often observed to collect on corrosion product in the meniscus after extensive LAI corrosion. Additionally, LAI corrosion initiated later than crevice corrosion in the presence of a crevice. The effect of meniscus geometry on LAI corrosion initiation depends on the precise triple phase boundary rather than the opening angle of the meniscus geometry. Deaeration accelerated LAI corrosion. LAI corrosion was not enhanced by wetting the surface immediately above the meniscus. A pre-existing passive film boundary in the bulk solution could not eliminate LAI corrosion. Cyclic potentiodynamic polarization measurements were conducted, but could not distinguish the solution aggressiveness in terms of passive current density and pitting potential at varied alkaline pHs and concentrations of nitrate and nitrite ions. In addition, linear polarization resistance and electrochemical impedance spectroscopy measurements at OCP in the meniscus and bulk solution could not confirm the hypothesis that the meniscus solution would become increasingly aggressive to initiate LAI corrosion. Efforts were made to generate direct supporting evidence for several hypotheses. The use of a small pH electrode did not confirm existence of a pH gradient before initiation of LAI corrosion. Similarly, no IR drop was present in the meniscus prior to LAI corrosion initiation. In situ Raman spectroscopy was applied to monitor concentration changes of nitrate, sulfate and nitrite with time in the meniscus during LAI corrosion. A proposed mechanism of nitrate ion enhancement and nitrite ion depletion at (open full item for complete abstract)

Committee: Gerald Frankel (Advisor); Rudolph Buchheit (Committee Member); Yogeshwar Sahai (Committee Member) Subjects: Materials Science

PhD, University of Cincinnati, 2024, Arts and Sciences: Chemistry

Self-assembled monolayers (SAMs) of alkanethiols on gold surfaces are pivotal in the realm of controllable surface chemistry due to their ease of formation from the solution phase and the ability to be characterized through various techniques. Understanding the nanoscale formation processes of SAMs is essential for creating defect-free SAMs tailored for applications in bio- and nanotechnology. While numerous studies have focused on characterizing SAMs post-formation, the process at the nanoscale has been less explored. This thesis delves into the formation and controlled desorption of SAMs on gold, alongside the development of electrochemical aptamer-based (E-AB) sensors on microelectrode platforms. In the first project, we investigate the formation of defect-free SAMs and the underlying mechanisms at the nanoscale. Using scanning electrochemical cell microscopy (SECCM), we monitored SAM formation via a soluble redox reporter on a polycrystalline gold foil through voltammetric and amperometric techniques. By varying the concentration of 3-mercapto-1-propanol [HS(CH2)3OH], 6-mercapto-1-hexanol [HS(CH2)6OH], and 9-mercapto-1-nonanol [HS(CH2)9OH], we assessed the effects of thiol chain length, concentration, and substrate location on monolayer formation. Our findings indicate that SAM formation is concentration-dependent and varies at grain boundaries, with real-time changes in the quasi-steady-state current observed during the self-assembly process. The second project focuses on the controlled desorption of self-assembled thiol monolayers on gold surfaces, aiming to enable precise surface engineering for diverse applications in surface science, nanotechnology, and biomedicine. Employing SECCM, we investigated the substrate and potential-dependent desorption process, highlighting the influence of alkanethiol chain length and substrate crystallinity. Our study provided significant insights into the desorption behavior at the nanoscale, revealing phenomena obscured (open full item for complete abstract)

Committee: Ryan White Ph.D. (Committee Chair); Ashley Ross Ph.D. (Committee Member); Noe Alvarez Ph.D. (Committee Member) Subjects: Chemistry

Doctor of Philosophy, University of Akron, 2022, Chemical Engineering

Microbiologically influenced corrosion (MIC) is a common problem that affects various industries. Monitoring and detecting MIC inside of pipelines has been challenging mainly because there is little to no research work being conducted accounting for all variables together such as flow, microorganism, and corrosion. Above all, MIC is hard to detect and the mechanisms by which MIC occurs are not completely understood. In this work, MIC is studied under a variety of conditions to begin to develop novel ways to validate mechanisms by which MIC occurs which can lead to new detection methods. First MIC is studied with a newly designed flow chamber to study MIC accounting for three variables: fluid dynamics, microorganisms, and corrosion. Second, the highly debated mechanism of sulfate-reducing bacteria (SRB) is studied using the split-cell zero resistance ammetry (SC-ZRA) technique. Flow chamber is developed as a quick tool in the lab to determine how MIC is affected inside of pipelines in the presence of microorganisms under hydrodynamic conditions in oxygen-limited and oxygen non-limited conditions. Mass transfer properties (i.e., shear stress, velocity, and mass transfer coefficient) of the system were evaluated using rotating cylinder electrode experiments. The flow system was then used to study the impact of mass transport on MIC in oxygen-non-limited and oxygen-limited microbial incubations using Shewanella oneidensis as a model organism. SC-ZRA work shows that during the initial stage of the SRB biofilm attachment (14 days), the area under the biofilm acts as an anode and the uncovered region acts as a cathode. During the first 14 days of inoculation, chemical microbially influenced corrosion (CMIC) is the dominant mechanism for SRB metabolism. When the corrosion products accumulate on the biofilm after 14 days, the area under the biofilm acts as a cathode and the uncovered region acts as an anode. When the metal surface is completely covered by corrosion product (open full item for complete abstract)

Committee: Hongbo Cong (Advisor); John Senko (Committee Member); Gopal Nadkarni (Committee Member); Qixin Zhou (Committee Member); David Bastidas (Committee Member) Subjects: Biochemistry; Chemical Engineering; Microbiology

Doctor of Philosophy (PhD), Ohio University, 2020, Chemical Engineering (Engineering and Technology)

Growing renewable energy technologies is not only essential to reduce carbon emissions and mitigate climate change, but also critical to boost global energy security and support a sustainable basis for economic development. Prioritizing new technologies that promote the transition from fossil fuels to renewable energy technologies is critical to address future global energy demands and prevent global warming. Lignin is a major renewable and non-fossil source of aromatic compounds that can be used to generate sustainable fuels, fine chemicals, additives, and resins. The application of lignin, however, as a source of aromatic compounds has been largely undeveloped due to the lack of an efficient depolymerization process. Among various methods that have been developed so far for lignin depolymerization, electrochemical conversion is a promising approach for industrial application because it occurs at room temperature and ambient pressure. Nickel-based and lead dioxide-based materials are among the most common electrocatalysts for lignin oxidation, as both are inexpensive and stable in highly alkaline electrolytes, and possess high catalytic activities for lignin oxidation. In this Ph.D. project, several nickel-based alloys were developed through co-electrodeposition of nickel and cobalt; and nickel and tin, to enhance the properties of the nickel catalysts for lignin depolymerization. Incorporation of cobalt to nickel reduces the onset potential for lignin oxidation due to the enhanced properties resulting from doping cobalt to nickel. Electrochemical oxidation of lignin on nickel-cobalt alloys with a higher cobalt content leads to lower energy requirements for lignin depolymerization and higher rates of formation of the functionalized aromatic compounds. Nickel-tin alloys provide higher surface areas and better stabilities for long term lignin oxidation. Lignin depolymerization is the dominant reaction at the low cell voltages when the oxygen evolution faradaic effici (open full item for complete abstract)

Committee: John Staser (Advisor); Rebecca Barlag (Committee Member); Sarah Davis (Committee Member); Kevin Crist (Committee Member); Marc Singer (Committee Member) Subjects: Chemical Engineering

Doctor of Philosophy, Case Western Reserve University, 2019, EMC - Mechanical Engineering

Redox flow batteries with flow field designs have been demonstrated to boost their capacities to deliver high current density in medium and large-scale energy storage applications. Nevertheless, the fundamental mechanisms involved with improved current density in flow batteries with serpentine flow field designs have been not fully understood. In this dissertation work, one-dimensional (1D) analytical model, two-dimensional (2D) numerical model with scaling analysis, and three-dimensional (3D) model of a serpentine flow field over the porous carbon paper electrodes have been developed to examine the distributions and amounts of pressure driven electrolyte flow penetrations into the porous carbon paper electrodes. It was found that the electrolyte flow penetrations are strongly under-estimated by 1D analytical model and 2D numerical model. The scaling analysis also demonstrates that the flow penetrations enhanced by the adjacent flow channels are significant, and were not able to be incorporated in the 1D and 2D models. The 3D model accounts the effects of landings/ribs bridged between the adjacent flow channels on flow penetrations and better calculates the amount of flow penetrations into the porous carbon paper electrodes. It was also found that the flow penetrations are sensitive to the properties of the porous electrode, i.e. permeability and porosity, a smaller permeability or porosity results in a much smaller flow penetration. The model is used to estimate the maximum current densities associated with the stoichiometric availability of electrolyte reactant flow penetrations through the porous carbon paper electrodes. The modeling results match reasonably well observed experimental data without using any adjustable parameters. This fundamental work on electrolyte flow distributions of limiting reactant availability will contribute to a better understanding of limits on electrochemical performance in flow batteries with serpentine flow field designs and should (open full item for complete abstract)

Committee: Robert Savinell (Advisor); Joseph Prahl (Advisor); Jesse Wainright (Advisor); Paul Barnhart (Committee Chair); Sunniva Collins (Committee Member); James T'ien (Committee Member) Subjects: Applied Mathematics; Chemical Engineering; Energy; Fluid Dynamics; Mechanical Engineering; Physics

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2018, Photochemical Sciences

Proteins play a central role in biological processes. Broad classes of protein types are involved in the innumerable functions of living systems, such as catalysis of the biochemical reactions, transportation of the essential molecules, defense of the immune system, and the transmission of messages from cells to cells. In our projects, we have combined the analytical approaches including surface-enhanced Raman scattering (SERS), fluorescence microscopy, electrochemistry, and computational methods to investigate the structures and functions of the proteins and signaling molecules in the living cells. In our research, we have studied the interactions and functions of dopamine transporters (DAT), dopamine receptors (DARs), and several signaling molecules such as dopamine (DA), amphetamine (AMP), methamphetamine (MAMP), and methylenedioxypyrovalerone (MDPV) in living cells. The interactions between signaling molecules and DAT or DARs are crucial for the functioning of dopaminergic pathways. In our project, we have probed interactions of signaling proteins including DAT and DARs and investigated the changes that happen in signaling proteins, other interacting compounds or intracellular contents of the second messenger such as cyclic adenosine monophosphate (cAMP). The second messenger like cAMP is important in many biological processes which are produced due to interactions of the signaling protein in living cells. Our studies on DA-DAT or DA-DARs interactions mainly utilize the Raman spectroscopy to characterize the selectivity and efficacy of psychopharmaceutic drugs. In addition, we have also studied the redox states and mechanism of protein cofactors in different experimental conditions. We have probed and characterized the redox states and mechanisms of FMN cofactors in biological and non-biological environments using electrochemistry, SERS measurements, and computational measurements. The results obtained from our research could be useful in the diagnosis of abnorm (open full item for complete abstract)

Committee: H Peter Lu PhD (Advisor); John R Cable PhD (Committee Member); Alexey T Zayak PhD (Committee Member); Anita Simic PhD (Other) Subjects: Chemistry

Master of Sciences, Case Western Reserve University, 2017, Materials Science and Engineering

The performance of solid oxide fuel cells (SOFCs) with three different lanthanum strontium manganite (LSM) based cathode compositions were evaluated. All cells were yttria-stabilized zirconia (Zr0.92Y0.08O2-d, 8YSZ) electrolyte-supported button cells, consisting of a nickel oxide – yttria-stabilized zirconia (NiO-8YSZ) anode and a cathode of 8YSZ and LSM. The three LSM compositions differed in the amount of excess Mn: Composition A was (La0.85Sr0.15)0.90MnO3±d (10% excess Mn); Composition B was (La0.80Sr0.20)0.95MnO3±d (5% excess Mn); and Composition C was (La0.80Sr0.20)0.98MnO3±d (2% excess Mn). The cells were tested under conventional and accelerated conditions, where the accelerated conditions were meant to simulate the results of months of long-term testing in just 500 hours (approximately three weeks) of testing by using high operating temperature and current density. Accelerated tests showed lower degradation rates, lower continuous area specific resistance (ASR), and higher power output than conventional tests for all cathode compositions. Continuous measurements of the cells' output voltage versus time, together with periodic electrochemical impedance spectroscopy (EIS) measurements, were used to evaluate the performance of the cells in terms of ASR degradation rates (% ASR rise per kh) and power outputs. The EIS measurements also permitted a partial deconvolution of the cathode ASR from the anode ASR. Cathodes with 10% excess Mn tested under accelerated conditions had the lowest degradation rates, but the highest continuous ASR and lowest power outputs. Cathodes with 2% excess Mn tested under accelerated conditions had the lowest continuous ASR and highest power outputs; thus it was concluded that cells with the lowest amount of excess Mn cathodes performed the best.

Committee: Mark De Guire (Advisor); Arthur Heuer (Committee Member); Roger French (Committee Member) Subjects: Energy; Materials Science

Master of Science, The Ohio State University, 2013, Mechanical Engineering

Lithium-ion (Li-ion) batteries have become very prominent as a form of energy storage for numerous applications due to its high energy and power densities. They are used for numerous portable devices and more recent electric vehicles (EVs). It is important to increase the cycle life of Li-ion batteries in order for them to be more viable for the automotive industry. With use, these batteries undergo an aging process which reduces the battery storage capacity and increases internal resistance. To reduce the aging process it is essential to first understand the degradation mechanisms on the electrodes of the battery. A multi-scaled approach has been previously applied to the study of the degradation of the LiFePO4 cathodes. It has been shown that nanoparticles in cathodes coarsen as a result of aging. Coarsening of nanoparticles has been shown to lead to an increase in surface resistance and decrease in surface conductivity, which is responsible for reduced lithium retaining capacity. It is therefore important to study the cause of these aging mechanisms in order to increase the life of the battery. An in depth study of cathode on the nanometer scale is necessary using atomic force microscope (AFM) related techniques. In this work, both ex-situ and in-situ studies were conducted to understand the aging phenomenon in LiFePO4 battery cathodes. High resolution AFM imaging and current measurements were conducted to study the difference of the unaged cathode from the aged. This was done to quantify the coarsening process. Particle agglomeration was observed in the aged cathode, which is believed to reduce surface conductivity. Nanomechanical characterization and mechanical integrity studies were then conducted on unaged and aged cathodes using AFM equipped with nanoindentor. This was done to determine the effect of increased internal stress within the cathode created during aging on the nanomechanical and mechanical integrity properties. Propertie (open full item for complete abstract)

Committee: Bharat Bhushan (Advisor) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2013, Food, Agricultural and Biological Engineering

Microbial fuel cells (MFCs) are bio-reactors in which bacteria undergoing anaerobic respiration, deprived of all common electron acceptors, are able to use a final electron acceptor outside of the cell wall. While MFCs are able to directly convert almost any nutrient source into electricity, the voltage and current produced are too low to power common electrical devices. Due to the biological nature of the electricity production, the traditional method of stacking voltage sources in series to increase the amplitude does not work. This experiment tested the ability of passive circuits to boost the voltage output of MFCs and the effect of those circuits on the MFCs themselves. The circuit known as the Joule Thief successfully boosted the voltage of four MFCs in parallel while also reducing the activation losses of these cells.

Committee: Ann Christy PhD, P.E. (Advisor); Olli Tuovinen PhD (Committee Member); Lingying Zhao PhD (Committee Member) Subjects: Energy; Engineering; Microbiology

MS, University of Cincinnati, 2005, Engineering : Environmental Engineering

Wastewaters from textile dyeing operations often contain organics compounds with strong color accompanied by a high concentration of sodium chloride (NaCl), and electrochemical treatment is a promising way to treat the waste. The objective of this investigation was to evaluate the impact of design and operational parameters on decolorization efficiency and effluent toxicity during electrochemical treatment of wastewater containing the dye Acid Alizarin Violet N (AAVN; 14.65 mg/L) and NaCl (0.35 M). Cell configuration (split and undivided) and electrical current density (4 and 8 mA/cm 2 ) were the chosen reactor design parameters and pH (4, 7 and 10) and applied current (72 and 144 mA) were the chosen operational parameters. Extent of removal, power consumption, and effluent toxicity were the design criteria signifying efficiency, cost effectiveness, and environmental impact of the process. The split cell configuration provided the highest color removal, consuming significantly lower power than the undivided cell. Extent of decolorization was higher at pH 4 than that at pH 10 and pH 7. Increasing applied current increased the extent of color removal in the split cell whereas performance was unaffected in the undivided cell. Microtox ® toxicity test showed that effluents collected from more efficient conditions (split cell at pH 4) revealed the highest toxicity. In contrast, negligible toxicity was found in the effluent from the least efficient undivided cell - pH 10 conditions. A design strategy that maximizes the efficiency is in direct conflict with the goal of minimizing effluent toxicity. This study demonstrates the importance of considering end product toxicity in addition to more traditional criteria in making suitable decisions for electrochemical reactor design.

Committee: Dr. Margaret Kupferle (Advisor) Subjects: Engineering, Environmental

Master of Science, University of Toledo, 2009, Chemistry

A cadmium sulfide / cadmium telluride (CdS/CdTe) solar cell consists of thedevice stack: Glass substrate / SnO2:F (TCO, transparent conductive oxide) / CdS (n-type semiconductor) / CdTe (p-type semiconductor) / Cu/Au (metal/back contact). During the fabrication process of the CdS and CdTe thin films pinholes are usually formed within these layers (random defects, which are entropy driven). After the semiconductor deposition, and subsequent heat treatments, the solar cell is completed with the deposition of a metal electrode onto the CdTe surface. The presence of a pinhole through the semiconductor layers leads to the formation of a wire like connection through the photovoltaic device (shunt, metal connection of the TCO and metal electrodes), which adversely affects the overall performance of the solar cell. Our proposed solution is to fill these pinholes with a resistive material such as polyaniline, using an electrochemical deposition (electrochemical polymerization) technique. The electrochemical deposition technique is performed by applying a voltage across a conductive substrate (TCO coated glass) and an inert electrode (Pt), both placed inside an electrolyte rich solution containing aniline. The aniline monomer then reacts at the positively charged conductive substrate to form a polymer (polyaniline). After the polyaniline film deposition, this new layer acts as an insulating layer, preventing the back contact (Cu/Au) from electrically contacting the TCO layer, thus avoiding shunting of the solar cell. Characterization techniques employed in this study are: depth profilemeter, x-ray photoelectron spectroscopy, electron spray ionization - mass spectrometry, scanning electron microscopy, energy dispersive spectroscopy and grazing angle incidence x-ray diffraction. Subsequently, this technique is applied to CdTe solar cells that have pinholes and on an artificially scribed pinhole. After the electro deposition of polyaniline the CdTe solar cell is completed by met (open full item for complete abstract)

Committee: Dean Giolando M (Advisor); Terry Bigioni (Committee Member); Cora Lind (Committee Member) Subjects: Chemical Engineering; Chemistry; Energy; Engineering; Experiments; Materials Science; Physics; Polymers

Doctor of Philosophy, The Ohio State University, 2005, Materials Science and Engineering

High strength aluminum alloys typically used in the aerospace industry are provided with coatings for corrosion protection. One of the coating layers is the primer, containing corrosion inhibiting pigments. Conventionally chromate pigments have been used but they are carcinogenic; so there is a need to develop environment-friendly alternatives that can match the corrosion inhibition of chromates. In this study, the use of hydrotalcites as corrosion-inhibiting pigments in organic coatings has been explored. Hydrotalcites are anion clays with excellent ion-exchange capabilities, and for this reason they have been used in industry as anion scavengers. Vanadates are excellent inhibitors of Al alloy corrosion. A Zn-Al-decavanadate hydrotalcite (HT-V) was synthesized and its ion exchange properties characterized. From instrumental neutron activation studies, it was determined that inhibitor release was a small fraction of the total inhibitor in the pigment. However, this was sufficient to provide appreciable corrosion inhibition to Al alloys during potentiodynamic polarization. Additionally, inhibitor release occurred even when these pigments were dispersed in epoxy resins and applied to Al alloys. A bare surface in close proximity to the coating was also inhibited from corrosion. Lastly, coatings containing the HT-V pigment performed well in a salt spray environment, protecting scribe corrosion upto ~1000 h exposure. Blistering problems encountered during this test were overcome by silane additions to the coating, which improved adhesion and controlled blistering.

Committee: Rudolph Buchheit (Advisor) Subjects: Engineering, Materials Science

Doctor of Philosophy (PhD), Ohio University, 2008, Chemical Engineering (Engineering and Technology)

Lanthanum strontium vanadate (LSV), a perovskite ceramic electrocatalyst suitable for use as a solid oxide fuel cell (SOFC) anode, has shown significant activity toward the selective oxidation of H2S from a fuel stream. With this in mind, the feasibility of a two-stage SOFC reaction process using LSV-based SOFCs as an alternative to H2S sorbents was investigated. A procedure for producing a bilayer LSV anode via an inexpensive screen-printing method was optimized and planar SOFCs utilizing these bilayer LSV anodes were tested under H2, syngas and syngas with H2S environments. Considering LSV/yttria stabilized zirconia (YSZ) bilayer anodes, it was found that the optimum anode thickness of 65 μm at 800°C yields a maximum power density of 5.85 mW/cm2, while at 900°C the optimized anode thickness of 80 μm realizes a maximum power density of 17.96 mW/cm2. Substitution of gadolinium-doped ceria (GDC) for YSZ in the bilayer LSV anode was shown to improve catalytic performance; peak power densities for optimized LSV/GDC-based SOFCs at 800 and 900°C were 16.60 and 34.86 mW/cm2, respectively.It was demonstrated that all tested LSV-based SOFCs showed little to no performance degradation due to catalytic poisoning when utilizing syngas containing H2S as fuel, corroborating previous results. It was also shown that LSV had poor activity toward CO oxidation either directly or as a water-gas shift catalyst over the tested temperature range. A feasibility study of the aforementioned two-stage SOFC reaction process showed that SO2 found in the exhaust from the LSV-based SOFC caused performance degradation to a Ni-based SOFC, though not to the extent caused by an equal amount of H2S; this finding suggests that SOFCs utilizing LSV/YSZ anodes may indeed offer promise as a method for warm-gas remediation of H2S contained in hydrocarbon fuel streams.

Committee: David J. Bayless PhD (Advisor); Michael Prudich PhD (Committee Member); Howard Dewald PhD (Committee Member); Daniel Gulino PhD (Committee Member); Jeffrey Rack PhD (Committee Member) Subjects: Chemical Engineering

Doctor of Philosophy, University of Akron, 2008, Electrical Engineering

This dissertation presents a methodology for using cycling data collected from several similar electrochemical cells to generate an aging model that predicts how the parameters in a first-principles dynamic model of a cell will change as the cell ages. Nine standard 18650 lithium-ion cells were cycled in three sets. Aging models were applied to the identified parameters of the dynamic models. These aging models were then validated by comparing their predictions with the original cycle data resulting in RMS voltage errors of less than 5% over the entire life of the cells. These aging models provide an accurate means of predicting the parameters for the dynamic cell model based on the life fraction of the cell and the maximum charging voltage. Unlike other aging models presented in the literature, the aging models presented here address the external performance of the cells. The aging model containing first-order temperature correction terms for the charge diffusion and current polarization term produced the smallest errors when compared with the original data. Incorporation of the aging model into a battery management system (BMS) will allow the BMS to better track capacity and remaining life of a cell. The methodology presented here could be applied to other cell chemistries.

Committee: Tom Hartley PhD (Advisor) Subjects: Chemical Engineering; Electrical Engineering

Doctor of Philosophy, University of Akron, 2008, Chemical Engineering

Hydrogen has been the most common fuel used for the fuel cell research but there remains challenging technological hurdles and storage issues with hydrogen fuel. The direct electrochemical oxidation of CH4 (a major component of natural gas) in a solid oxide fuel cell (SOFC) to generate electricity has a potential of commercialization in the area of auxiliary and portable power units and battery chargers. They offer significant advantages over an external reformer based SOFC, namely, (i) simplicity in the overall system architecture and balance of plant, (ii) more efficient and (iii) availability of constant concentration of fuel in the anode compartment of SOFC providing stability factor. The extreme operational temperature of a SOFC at 700-1000 °C provides a thermodynamically favorable pathway to deposit carbon on the most commonly used Ni anode from CH4 according to the following reaction (CH4 = C + 2H2), thus deteriorating the cell performance, stability and durability. The coking problem on the anode has been a serious and challenging issue faced by the catalyst research community worldwide. This dissertation presents (i) a novel fabricated bi-metallic Cu-Ni anode by electroless plating of Cu on Ni anode demonstrating significantly reduced or negligible coke deposition on the anode for CH4 and natural gas fuel after long term exposure, (ii) a thorough microstructural examination of Ni and Cu-Ni anode exposed to H2, CH4 and natural gas after long term exposure at 750 °C by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction and (iii) in situ electrochemical analysis of Ni and Cu-Ni for H2, CH4 and natural gas during long term exposure at 750 °C by impedance spectroscopy. A careful investigation of variation in the microstructure and performance characteristics (voltage-current curve and impedance) of Ni and Cu-Ni anode before and after a long term exposure of CH4 and natural gas would allow us to test the validation of a negl (open full item for complete abstract)

Committee: Steven Chuang PhD (Advisor); Lu-Kwang Ju PhD (Committee Member); George Chase PhD (Committee Member); Jerry Young PhD (Committee Member); Chris Miller PhD (Committee Member) Subjects: Chemical Engineering