Advanced fuel economies in both traditional internal combustion engine vehicles (ICEs) and electric vehicles (EVs) have a strong influence on transportation revenue by reducing fuel consumption per vehicle and ultimately drawing down the amount of fuel tax revenue received. It is expected that more ICE vehicle with advanced fuel economies and electric vehicles, especially gasoline hybrid electric vehicles, will enter the roadway in coming years, and fuel tax revenues and the Highway Trust Fund will increasingly become more affected. This study estimates the impact that increased sales of advanced ICEs and EVs will have on future fuel tax revenues by drawing on industry estimates of future EV and ICE market shares and anticipates future fleet mix and fuel economy for both vehicle technologies. An estimation process overview is provided and assumptions are described. Fuel tax revenue amounts that would be expected from future light vehicle fleets with increased shares of EVs are compared to equally sized fleets comprised of all ICEs, and future fleet mixes are estimated. Results show that as more electric vehicles enter the light vehicle fleet, greater revenue losses are expected, and total losses from years 2011 through 2050 depend on fleet composition and fuel economy of both vehicle types. Finally, it is found that the amount of fuel taxes paid by ICE drivers each year remain greater than fuel taxes paid by EV drivers even with advances in the average ICE vehicle fuel economy. / text

Solid oxide fuel cells (SOFC), owing to its high operating temperatures, have many advantages over other types of fuel cells. Its commercialization, however, relies greatly on its costs and long term durability. By reducing the operating temperature to the intermediate temperature range, the costs for the balance of plant would be significantly reduced. The greatest contribution to cell over-potential at this temperature range is the oxygen reduction at cathode; hence development of a cathode material with low specific resistance and durability would have direct impact on the commercialization of SOFC. Composite cathode is a common strategy used by many to improve cathode performance. This was done conventionally by random mixing of cathode material with a better ionic conductor such as the electrolyte material. Impregnation or infiltration is often used to improve interconnectivity among individual phases in the composite, In this study, fabrication of a composite cathode with two phases - gadolinium doped ceria (GDC) and platinum attempted, forming two inter-locked networks each with a channel dimension in the nanometer range by hard templating and chemical vapor infiltration (CVI) both for the first time to the best of my knowledge. It was found that surface layer of these materials play a very important role in the performance and structural stability. Another set of composite cathode was fabricated by packing commercially available GDC with carbon pore-former following by impregnation with Pt/Ag-Pt alloy. By introducing small amount of silver (6wt%), area specific resistance of 0.94cm2 and 0.16cm2 were observed at 550C and 660C, respectively during impedance spectroscopy in symmetrical cell arrangement. Silver was proposed to provide greater effective surface area for surface exchange and extending the triple phase boundary. Platinum was also suggested to provide a surface where silver wetting is possible stabilizing morphology of silver in the GDC scaffold. Platinum is not a practical choice of electrode material due to its costs and lower performance, it was chosen to demonstrate the strategy of vapor phase infiltration in fabricating SOFC composite cathode. However, the technique of CVI demonstrated can potentially be applied to other cathode candidate materials. / published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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The electrochemical performance of a polymer electrolyte membrane fuel cell is known to be dominated by the cathode processes comprising the various reaction and transport steps in the overall oxygen electro-reduction to water occurring in the catalyst layer (CL). This thesis is concerned with one such transport process – oxygen transport in ionomer phase of the CL – and the synthesis/characterization of platinum catalyst on an alternative support – carbon nanotubes (CNT). Specifically, the objectives of the thesis are: (i) exploration of methods for determining the effective permeability of oxygen in the ionomer phase of the carbon-ionomer composite representing the PEMFC catalyst layer (ii) synthesis of Pt/CNT catalysts and characterization thereof. An electrochemical method for determination of oxygen permeability in Nafion and Nafion-carbon composite films was explored. Since the method is suitable for dense films, mathematical model for data analysis had to be modified to allow treatment of porous films. Applying the modified model to the porous Nafion film, the oxygen permeation in the Nafion phase was found to agree with the literature data for oxygen permeation in Nafion membranes. However, no relationship between the effective permeability and ionomer content was found. Two methods for synthesis of Pt/CNT catalysts were studied – the precipitation method and the colloidal/ethylene glycol method. Functionalization of CNTs was found to be critical to obtaining any significant amount of Pt deposition on CNT. The precipitation method did not yield reproducible results. Pt/CNT catalysts of desired properties were synthesized via the colloidal/EG method. It was found that a high pH of 8.5 to 10.5 resulted in smallest Pt particle size. The Pt particles size was determined to range 2-4 nm. The synthesized Pt/CNT catalysts were also tested in a fuel cell environment. Steady-state polarization curves in humidified H2/Air system were obtained that demonstrated performance comparable to commercial electrodes in that cell potential of greater than 0.6 V at current density of 800 mA/cm2 electrode area and a limiting current density of 1200 mA/cm2 electrode area were observed. / Thesis (Master, Chemical Engineering) -- Queen's University, 2009-01-13 14:46:53.853

This thesis investigates the possibility of using electrokinetic effects, induced when a colloidal system is subjected to an electric field, to produce deterministic structure in the catalyst layer of polymer electrolyte membrane fuel cells. The susceptibility of the catalyst ink system to electrokinetic effects is clearly demonstrated. A novel apparatus and procedure is developed to allow for the formation of continuous films between two electrode surfaces through solvent evaporation. Characterization of the resulting layers is done through imaging and rotating disc electrode measurements. While the images show some possibility of structure formation, no clear increase in the oxygen reduction rate is observed. Recommendations for extending this work are provided. / Thesis (Master, Chemical Engineering) -- Queen's University, 2010-01-06 17:29:23.27

Heavy fuel oils (HFO) are produced from the refining of crude oils, and have high specific gravities and high viscosities. In recent years, spills of HFO have increased in the environment, and are of great concern because they are difficult to clean up. Spilled HFO is likely to become submerged, and can become stranded if fresh HFO coats benthic substrates or if weathered HFO sinks as tarballs. Conversely, lighter oils float on the surface and their components disperse and become diluted in the water column. There is a research need to assess the unique ecological risks of HFO that can sink and contaminate spawning shoals of fish. Chronic toxicity of HFO to fish embryos is correlated with exposure to polycyclic aromatic hydrocarbon (PAH) that become bioavailable from spilled HFO to identify under which spill conditions fish populations are at greatest risk. The results of this research demonstrate that: (1) Stranded HFO is a significant source of PAH to the receiving environment and causes chronic toxicity to embryonic fish; (2) Tarballs and weathered HFO cause less toxicity than fresh HFO, likely a consequence of physical limitations to PAH release; (3) HFO 7102 samples collected from an HFO spill in Wabamun Lake, Alberta, are less toxic than HFO 6303; (4) HFO is at least 2-fold more toxic than Medium South American (MESA), a well-studied reference crude oil, coincident with 3-fold higher concentrations of alkyl PAH, namely alkyl phenanthrenes. / Thesis (Master, Biology) -- Queen's University, 2011-07-25 10:43:05.759

Cost reduction is driving the development of solid oxide fuel cell (SOFC) technology for operations at lower temperatures (500 °C -700 °C) so as to allow the usage of cheaper balance-of-plant components and enhance the durability of the stack. However, lower temperatures adversely affect the overall performance of the cell and most notably that of the cathode. Development of cathode material exhibiting high performance at lower temperature is one of the goals of SOFC research and development. This thesis work is concerned with two distinct aspects of SOFC cathode development – one concerned with the stability of a recently studied cathode material, La0.5Ba0.5CoO3-δ (LBC), in CO2 containing atmosphere and another concerned with the development of methods for fabrication of reproducible electrodes and rapid electrochemical testing thereof. The study of reaction between LBC and CO2 was carried using a combination of thermogravimetric analysis (TGA), ex-situ X-Ray Diffraction (XRD) of products from TGA experiments and in-situ high-temperature XRD of LBC-CO2 mixtures. The mass change observed during TGA was combined with ex-situ XRD analyses of solid material phases to deduce the overall reactions. In-situ XRD measurements allowed for studying the intermediate reaction products. Isothermal studies at different temperatures in pure CO2 yielded kinetics for the reaction between LBC and CO2. Overall reaction pathway was proposed from these data. In addition, experiments were carried out to determine the thermodynamic carbonate formation temperature at a fixed CO2 partial pressure (pCO2). From the thermodynamic analysis of carbonate formation temperature at three different pCO2, the standard state enthalpy and entropy for the carbonate formation reaction were determined. This work is the first known in-depth study of reaction between LBC and CO2. The second distinct contribution of this thesis is the demonstration of a test system framework for fabricating reproducible miniature electrodes and rapid testing thereof. In particular, inkjet printing method was used to create well defined geometry of porous electrode and micro-contact impedance spectroscopy setup (MICS) was used to study the electrode electrochemical kinetics. The feasibility with electrode fabrication and electrochemical testing methods were demonstrated through the study of multiple silver miniature electrodes printed on single chip made of yttria-stabilized zirconia single crystal wafer. / Thesis (Master, Chemical Engineering) -- Queen's University, 2012-03-08 13:25:40.223