An Improved Pneumatic Frequency Control for Superconducting Cavities. GREGORY PUCKETT (Southern University and A&M College Baton Rouge, LA 70813) GARY ZINKANN (Argonne National Laboratory, Argonne, IL, 60439)

The ATLAS (Argonne Tandem Linear Accelerator System) super conducting cavities uses a pneumatic frequency control system to compensate for frequency deviations from the master oscillator frequency. The pneumatic frequency control unit was created in 1978 and has slew rates as low as 30 Hz/sec to 500 Hz/sec. The present system is slow in maintaining the master oscillator frequency due to frequency deviations. An improvement has been proposed that could reduce the time for the pneumatic frequency control system to reach the master oscillator frequency. Free hand sketches and computer software designs were implemented in the design stage of the new device. Frequency and physical displacement measurements were also taken and calculated to find that when the RF control module system is working properly the displacement can be kept within 6x10^-7 inches and the pressure can be controlled within 5x10^-4psi.

Analysis of Thermoxid Sorbents for the Separation and Purification of Molybdenum-99. HEATHER MAYES (University of Illinois at Chicago Chicago, IL 60607) CANDIDO PEREIRA (Argonne National Laboratory, Argonne, IL, 60439)

To address nuclear proliferation concerns, the Reduced Enrichment for Research and Test Reactor (RERTR) Program is investigating the technology needed to convert the nuclear reactors used for the production of ⁹⁹Mo which currently use high-enriched uranium (HEU, containing =20% 235U) targets, to use low-enriched uranium (LEU, containing =20% 235U) targets. The targets are dissolved in nitric acid. ⁹⁹Mo is subsequently recovered from the dissolved column by elution on an alumina column. To produce ⁹⁹Mo from an LEU target, approximately five times the uranium content is required, which poses challenges for separating the ⁹⁹Mo from the less-refined material since alumina is less effective at high uranium concentration. Using a more efficient sorbent to separate the ⁹⁹Mo from the dissolved target would allow for smaller purification columns and a limited amount of liquid waste. We have identified a sorbent produced by the Thermoxid Scientific and Production Company which selectively adsorbs molybdenum from solutions containing high concentrations of uranium. We tested this sorbent in a packed column with a solution simulating a dissolved LEU target. At flow rate of 3 mL/min through a 1 mL bed volume with 2 cm column height, thirty percent breakthrough was observed in eight bed volumes, and fifty percent in less than twenty-three bed volumes. Lowering the flow rate to 0.5 mL/min resulted in a fifty percent breakthrough in forty-five bed volumes. In both cases the adsorption appeared to be limited, with a high breakthrough corresponding to poor molybdenum retention. More studies will need to be completed to determine if modifying the experimental parameters could result in better molybdenum separation.

Calculation of Release Rates of Gaseous Species from Surfaces at Ultra-High Vacuum. STEVEN BENARIO (University of Illinois at Urbana Champaign Urbana, IL 61801) J.P ALLAIN (Argonne National Laboratory, Argonne, IL, 60439)

When performing surface interaction experiments at Ultra-High Vacuum, it is often important to have a detailed understanding of exactly what gaseous species are being generated and consumed by the chemical reaction taking place at the sample surface. There are not currently any tools available to distinguish between gaseous species of the same atomic mass. Using a linear analysis of partial pressure measurements by atomic mass along with known breakdown percentages of gaseous species by atomic mass, the process of determining partial pressure by species should be refined and automated. The present paper finds that by making use of the Moore-Penrose Matrix Inverse in a readily available programming environment, it is possible to calculate the partial pressures of gaseous species in a UHV environment using data from a residual gas analyzer. This allows for the direct and simple computation of generation and consumption rates of specific species in situ in a UHV research environment.

Construction of a Block on Ring test machine for the study of wear preventative properties of surface textures, coatings and lubricants. MICHAEL WAYNE (Brigham Young university Idaho Rexburg, ID 83460) GEORGE FENSKE (Argonne National Laboratory, Argonne, IL, 60439)

Much of industry is concerned with friction and wear of materials, especially in the use of bearings and gears which are used in engines and other machinery. Oil is commonly used to lubricate sliding surfaces. There are many failure modes in oil lubricated sliding. One especially severe mode is "scuffing". Scuffing is a point of lubrication and material failure that exhibits a sudden and extreme jump in friction force, resulting in large material wear. The construction of a block on ring test machine was done to further the study of scuffing, using various surfaces, coatings, and lubricants. The block on ring test machine, that was built, takes real time measurements of the load, speed, friction force, temperature and number of rotations that are made during the test through the use of data acquisition software. The principle of the block on ring test machine is that a stationary block, using pneumatic pressure is pushed with increasing force against a rotating ring, until scuffing occurs. Scuffing is said to occur when the friction coefficient suddenly increases ant the lubricating ability of the oil is lost. Tests were run of stock and polished steel specimens in (Mobil) PAO10 mineral oil, using a 22.3 N increase in load every minute until scuffing occurred. For a better understanding of scuffing, a test was stopped prior to scuffing in order to view the wear of contact areas. This test resulted in minimal wear as compared to tests where scuffing was allowed to occur. A repeat test was performed with polished specimens, which did not scuff, but resulted in the formation of an iron oxide and removal, and an increase in friction force, where the test was stopped for evaluation. Future experiments will involve the use of a hard carbon coating (Near Frictionless Carbon Coating-NFC6), a nitride coating, and laser surface textured (LST) specimens, where micro-dimples are made into the surface of the specimen to serve as lubricant reservoirs and to catch wear debris.

Database management for the Accelerator Systems Division Design and Drafting Group for the Advanced Photon Source of Argonne National Laboratory. RYAN KRONE (Valparaiso University Valparaiso, IN 46383) PAUL CHOI (Argonne National Laboratory, Argonne, IL, 60439)

The drawings prepared by the Design and Drafting Group represent every part that used in the construction of the APS. These drawings are all saved for reference in maintenance and improvements. A database called ProIntralink is used to store and organize the drawings. The management of these files is critical to reliability and productivity. My project was to organize these drawings using the Document Control Center Systems/Electronic DCN System, AutoCAD, ProEngineer, ProIntralink, and various websites and network drives. My first task working with the Design and Drafting Group was to organize recently finished drawings. I had to take the paper drawings and store them according to their WBS number. After the information for every part was correct, I had to open every part and make sure that its component interface attributes, mate and insert, were correct. I then worked on checking that all the files in ProIntralink have a WBS number. If they were missing or had an incorrect WBS number, it had to be properly labeled. The last project I worked on was to provide the documentation of various assemblies based on their parts list by printing a paper copy if necessary.

Database Management of AutoCAD and ProEngineering Drawing Using Intralink. ANDREW MIKLOS (University of Illinois at Chicago Chicago, IL 60561) PAUL CHOI (Argonne National Laboratory, Argonne, IL, 60439)

The Design and Drafting Group of the Accelerator Systems Division creates all the engineering drawings needed to manufacture parts for the Advanced Photon Source at Argonne National Laboratory. The purpose of this project was to ensure that all the completed drawings were organized into an electronic database. The first task was to reference the paper copies and organize them into filing cabinets as permanent references. Some of the drawings needed to be edited to ensure that they had the appropriate titles and attributes. Some drawings were created from scratch and provided to the machine shop to be manufactured. The final task was to check assemblies to learn what parts were pending or free. The result of this work will save the designers time when searching for and using drawings. By adding titles, the drawings can accessed easily. By adding attributes, the drawings have automatic features that make them more user friendly. In conclusion, this project work helped me to learn more about engineering as well as making a significant contribution to the efforts in my division.

FRICTION AND WEAR OF NFC-6 AND SUPER HARD COATINGS IN DRY NITROGEN, ISOBUTANE, AND HYDROGEN. FRANCISCO GUTIERREZ (Illinois Institute of Technology Chicago, IL 60629) GEORGE FENSKE (Argonne National Laboratory, Argonne, IL, 60439)

The purpose of the project is to assess the tribological parameters of Nearly Frictionless Carbon (NFC-6) and Super Hard Coating (SHC) on steel under dry nitrogen/Isobutane/Hydrogen environments. The speed, load, and environment were kept constant while considering the coated and uncoated surfaces as the independent parameters. A High Frequency Reciprocating Rig (HFRR) recorded the friction coefficient between the sliding surfaces. An optical profilometer was used to estimate the amount of material removed. An optical microscope was used for visual identification and measurement of coating thickness. Raman Spectroscopy was used to assist in determining whether the surfaces became more amorphous or crystalline. Overall results indicate that specimens under isobutane provide lower friction and higher wear resistance than specimens under hydrogen gas. The results indicate that a combination of bare steel/NFC6 ball and bare steel/NFC6 plate provides the lowest coefficient friction. NFC6 ball-SHC plate, NFC6 ball-NFC6 plate and NFC6 ball-Bare plate in hydrogen gas display short life (low wear resistance) but results display a coefficient of friction significantly smaller than any friction measured in isobutane. Future work should include revalidating some of the experiments for reliable results, introducing new independent variables such as speed, load and temperature. In addition, a detailed analysis of the surfaces in contact may provide an understanding at the microstructural level.

GREET Vehicle Cycle Model. UMUT OCAK (Pellissippi State Technical Community College Knoxville, TN 37933) PAULA MOON (Argonne National Laboratory, Argonne, IL, 60439)

The GREET vehicle model is a simulation of studies of energy use and emissions of vehicle cycles. It includes passenger cars, SUVs, minivans and heavy and light duty trucks. The types of vehicles are conventional cars, hybrid cars and fuel cell cars. The GREET vehicle model considers the energy used and emissions throughout the whole life cycle of these type of vehicles. This includes everything from the time the raw materials are acquired to disposal and recycling. This report focuses on the passenger car part of the vehicle cycle. The passenger car excel spreadsheet is a major part of the formula used in calculating the energy use and emissions of vehicles. In order to calculate the energy use and emissions, the material breakdown elements in the passenger car spreadsheet needed to be inputted for conventional, hybrid and fuel cell vehicles. The dismantling reports received from car manufacturers were one resource that was used for this project. These reports had the complete material breakdown of different vehicles. Other related reports were also used and experienced researchers of this study area were contacted for any information needed. After the passenger car spreadsheet dataset was complete, the energy use and emissions data were used after ensuring that the formulas were appropriate. The energy use and emission formulas were linked to passenger car spreadsheet and material spreadsheets.

Heat Exchanger Studies for Supercritical CO2 Power Conversion System. AKIRA TOKUHIRO (University of Missouri-Rolla Rolla, MO 65409-0170) STEVE LOMPERSKI (Argonne National Laboratory, Argonne, IL, 60439)

Recent investigations conducted under DOE Nuclear Energy Research Initiative program have demonstrated the benefits of the supercritical CO₂ power conversion system, including significant reductions in plants costs, size and complexity coupled with an increase in plant efficiency. The supercritical CO₂ power conversion system is being seriously considered for application to some of the Generation IV nuclear energy systems such as Gas (Cooled) Fast Reactor (GFR), Lead Fast Reactor (LFR) and Sodium Fast Reactor (SFR). It may also be adopted by the Very High Temperature Reactor (VHTR) for cogeneration of hydrogen and electricity. One of the key components for the supercritical CO₂ power system is the regenerative heat exchanger known as the recuperator where heat exchange between two flowing streams of supercritical CO₂ takes place. While the benefits of the supercritical CO₂ Brayton cycle derive from the unique thermophysical properties of supercritical CO₂ (e.g. density and specific heat), these same properties also present technical challenges to the recuperator design. To maximize the benefits of the supercritical CO₂ power conversion system, a compact heat exchanger would be required. Basic heat transfer data, such as heat exchanger performance data, under reactor-relevant conditions are needed in order to develop an improved design for application to the supercritical CO₂ power conversion system. The ANL-University of Missouri-Rolla (UMR) collaborative project has been awarded funding under the DOE Office of Nuclear Energy, Science and Technology (NE). The summer 2005 marks the start of the collaboration.

Medium Energy Sn⁺ Implantation in Ru Single Layer Mirrors. CHRISTOPHER CHROBAK (University of Wisconsin Madison, WI 53706) JEAN-PAUL ALLAIN (Argonne National Laboratory, Argonne, IL, 60439)

The process of energetically vaporizing, compressing, and ionizing materials produces various species of debris that is problematic for the lifetime of plasma-facing EUV (Extreme UltraViolet) collector optics. The IMPACT (Interaction of Materials with charged Particles And Components Testing) facility has been testing various collector optic samples under simulated charged particle irradiations to assess the effect of different debris species on the performance and thus the operational lifetimes of these optics. Tests include using ion beams to expose samples to controlled fluxes of mono-energetic Sn⁺ ions, an evaporator to direct thermal Sn flux onto samples, and annealing samples at high temperature (80-100 C). The effects of these exposures are monitored in situ using AES (Auger Electron Spectroscopy), LEISS (Low-Energy Ion Scattering Spectroscopy), and collection of sputtered atoms for mass measurement with a QCM-DCU (Quartz Crystal Microbalance - Dual Crystal Unit) system. In addition, the effects of exposures are measured ex-situ with AFM (Atomic Force Microscopy), XRR (X-Ray Reflectivity), and in-band EUV reflectivity. Results show convincingly through complementary metrology techniques that energetically implanted Sn atoms in Ru single layer mirrors diffuses readily, minimizing its impact on the mirror's EUV reflectivity.

Meteorological Modeling for the 2003 Mexico City Experiment. CARMEN THOMAS (Texas A&M University-Kingsville Kingsville, TX 78363) DR. RAO KOTAMARTHI (Argonne National Laboratory, Argonne, IL, 60439)

The impact anthropogenic activities have on the earth's atmosphere, biosphere and oceans is of increasing concern. Rapid industrialization and urbanization is contributing to a decrease in air quality across many parts of the earth. There are several scientific studies currently underway to understand and mitigate air quality problems in large urban centers with populations in excess of 10 million people, referred to as megacities. One such effort is the Megacities Impacts on Regional and Global Environments and exploratory field campaigns of the Mexico Valley Metropolitan Area (MVMA), conducted during April-May of the year 2003. During this period air pollutants such as NOx, ozone, and hydrocarbons variables were measurements. This data set provides the basis for a much larger Max-Mex project planned for March 2006 in the same region. The focus of Max-Mex is on understanding the regional-scale dispersion of aerosols generated in the Mexico City plume into the regional atmosphere, evaluating the sources, sinks and aging of black carbon and evaluating the radiative impacts as constrained by the measured aerosol physical and chemical properties and their distribution. Here we present results from a regional scale meteorological model (MM5) simulation for April 2003 over the Mexico City and surrounding regions. A nested version of the MM5 model with an outer 12km domain covering much of the country of Mexico and inner domain at a horizontal spatial resolution of 4 km, surrounding Mexico City and surroundings, was used for the simulations. The MM5 output was compared with data from several meteorological stations located within the model domain. The analysis showed the temperature to be within 2 0C of the measurements at one of the sites. Further analysis of the model results and preparation of dynamic inputs for a regional scale air quality model from these MM5 results will be performed in the near future.

Optimizing a Prototype for the Production of Medical Ice Slurry. JEFFREY MA (Stanford University Stanford, CA 94305) KEN KASZA (Argonne National Laboratory, Argonne, IL, 60439)

Injection of micro-particulate ice slurry to induce cell-protective hypothermia offers significant advantages over current techniques for internal organ cooling in surgical and medical emergency settings, including a faster cooling rate and higher cooling capacity. While a preliminary prototype machine has integrated ice slurry production into an automated, medical-grade process, a more exact understanding of specific components of the design is needed in order to improve its efficiency and slurry ice load. Using calorimetric quantification of ice loading as a measurement of the quality of the ice slurry, we tested several parameters influencing the production process, including mixer design, cooling optimization, processing time, and the physical contour of the machine reservoir as it affects mixing efficiency and subcooling. Through our tests, we have been able to achieve a 45% slurry ice load with reproducibility (improved from 25%), accumulate a better understanding of the factors affecting the production process, and establish an improved procedure and prototype for an ice slurry production machine. This reported work is part of a larger project to develop and implement a more effective technique of induced cell-protective hypothermia for cardiac arrest and stroke victims as well as patients of certain minimally invasive surgeries.

Pneumatic Shifter for 5-Speed Manual Transmission. SHAWN ALLRED (University of Wyoming Laramie, WY 82070) MIKE DUOBA (Argonne National Laboratory, Argonne, IL, 60439)

Over the course of this internship at the Advanced Power train Research Facility (APRF), I was challenged with many projects; the main one was to design a Pneumatic Shifter for a 5-Speed Manual Transmission. This task involved a lot of mechanical, electrical, fabrication, and programming work. The purpose of the pneumatic shifter is to be able to shift a standard 5-Speed manual transmission with the push of a button without the transmission actually being in the vehicle. This involved controlling two levers that have to be precisely moved into the right position at the right time with air cylinders and electronic solenoids to shift the devise called MATT. This is all going to shift a devise called MATT. It is simply a large metal platform on a rolling chassis that has been equipped with a gasoline engine and a scalable inertia 100Kw AC induction motor. These two are in-line allowing the use of just the gasoline engine, just the electric motor, or both to power the rear tires. The MATT platform emulates a hybrid electric vehicle. The 5-Speed transmission sits at the rear, just before the rear drive shaft. Future work will focus on using the MATT for testing other engines and motors including a hydrogen engine. The goal of this study is to study the impact of various degrees of hybridization on fuel economy, emissions, performance, cost, etc.

Synthesis of PLGA-mPEG Nanospheres by Combining Oil-in-Water Emulsion Solvent Evaporation and Nanoprecipitation Techniques. STAVAN PATEL (Cornell University Ithaca, NY 14850) MICHAEL KAMINSKI (Argonne National Laboratory, Argonne, IL, 60439)

The goal of this research project is to develop magnetic nanospheres for their use in toxin removal systems. Magnetic nanospheres encapsulated with magnetite, and their surface covered with ligands, which corresponds to specific toxins or antigens will be developed. These magnetic nanospheres will be intravenously injected into a human body where these particles will be able to bind to toxins such as cesium, anthrax lethal factor, risen toxin, and others present in the body. These magnetic nanospheres will be removed from the human body by allowing them to pass through a strong magnetic field. This research distribution of 75 nm, 120nm, 150nm, 200nm, and 250nm to ensure proper flow of nanospheres through the circulatory system, and to achieve toxin removal efficiency. The PLGA-mPEG block copolymer nanospheres were synthesized using a combination of oil-in-water emulsion solvent evaporation method, and nanoprecipitation techniques. Nanoprecipitation techniques is a one step nanosphere synthesis technique, which presents numerous advantages, in that it is a straight forward technique, rapid and easy to perform. It requires two miscible solvents and ideally the polymer should dissolve in the organic solvent, but not in the non-solvent. When the polymer/solvent solution is added to the non-solvent, under gentle stirring conditions, nanoprecipitation occurs by rapid desolvation of polymer. Oil-in-water emulsion solvent evaporation technique is a two step synthesis technique, which uses energy (ultrasound, vigorous mixing or both) to emulsify the immiscible organic and aqueous phases. Step one requires two completely immiscible solvents, where ideally the polymer is dissolved in the organic solvent and added to the inorganic non-solvent, while it is sonicated or vortexed for a short period of time. Step two requires that the emulsified solutions be stirred gently for 48 hrs - 96 hrs to completely evaporate the organic solvent from the emulsion. Generally, 100 nm -300 nm nanospheres with a narrow mono-modal distribution can be synthesized using the nanoprecipitation technique. To synthesize a nanosphere of size less that 100 nm, we combined the nanoprecipitation and the oil-in-water emulsion solvent evaporation technique, where energy of the oil-in-water emulsion solvent evaporation technique is used along with the nanoprecipitation solvents to generate emulsions.

The Hydrolysis Reaction of the Low Temperature, Hybrid, Thermochemical Cupric Chloride Cycle. MATHEW ROWE (Loisiana State University Baton Rouge, LA 70803) MICHELE LEWIS (Argonne National Laboratory, Argonne, IL, 60439)

Thermochemical cycles are being developed as an alternative and cleaner method in the production of hydrogen. Nuclear or solar energy sources will be utilized for the high energy demands of the thermochemical cycles. Our goal is to develop a cycle that has a maximum temperature of 550ºC, does not produce green house gases, does not run under extreme pressures or temperatures, and does not produce highly hazardous chemicals. The hydrolysis reaction is 2CuCl₂(s) + H₂O(g) CuCl₂ CuO(s) + 2HCl(g). The main objective was to determine both a viable reactor design and a complete system with the ability to control and maintain a constant water vapor content in the nitrogen carrier gas, system temperature, and system pressure. A fixed bed reactor design was utilized inside a Pyrex tube that was placed in a temperature controlled furnace. The overall system used two mass flow controllers, two cold water baths, saturation bubbler, hygrometer, temperature controlled furnace, and water trap to strip hydrogen chloride gas that was monitored by a pH meter. Initial results show a need for as much as sixteen parts water for every part cupric chloride, decomposition of cupric chloride to copper chloride at higher temperatures, and gas-solid particle contact problems. The use of air baffles before and after the reaction vessel has been employed to help with the contact problems. Also, lower temperatures are being used to help reduce the amount of decomposition of cupric chloride. The results suggest that a fluidized bed reactor should be employed to ensure proper contact of solid particles and gas to promote the reaction. The current overall system design has removed most of the instability in the system with only slight variations coming from the change in humidity and temperature in the laboratory. The current project is to institute a fluidized bed reactor and to update old equipment. In time, only two to six parts water to one part cupric chloride will be needed.

THERMAL STABILITY of LCLS FIXED SUPPORT. BHARAT THAKKAR (Illinois Institute of Technology Chicago, IL 60616) DR. SUSHIL SHARMA (Argonne National Laboratory, Argonne, IL, 60439)

The Linear Coherent Light Source (LCLS) will be hosted by the Stanford Linear Accelerator Center (SLAC). Currently, the project is in engineering & design phase. The undulator, support stands, and cam movers are being designed at APS. The thermal stability of the undulator support system was critically analyzed using finite element technique and the important thermo-mechanical parameters were experimentally verified. Change in position of undulator while the temperature fluctuates and any rapid changes in temperature were monitored for 35 hours continuously. With appropriate insulation, support material, and heat sink design; the design goal of variation in 0.7-meter stand height within plus or minus three microns was successfully achieved.

Thermal Stability of Linac Coherent Light Source Fixed Support. ALEJANDRO SAUCEDO (Illinois Institute of Technology Chicago, IL 60616) DR. SUSHIL SHARMA (Argonne National Laboratory, Argonne, IL, 60439)

Advanced Photon Source scientists at Argonne National Laboratory are designing a fixed support system for a 4th generation light source, the Linac Coherent Light Source (LCLS). It is required that this support system remain thermally stable while air temperature in the LCLS tunnel fluctuates. In this study, special emphasis was placed upon situations where rapid changes in temperature occur. Finite element analysis and transient heat transfer calculations were performed to predict and select the best design options. A cylindrical mild steel stand was chosen as the fixed support. This stand was insulated to dampen the temperature fluctuations. To record the changes in temperature, resistance temperature detectors and temperature transmitters were utilized. The experimental results show that the thermal insulation can eliminate the effect of rapid changes in air temperatures, and can reduce the effect of slow temperature change by a factor of three.

Use of a Superheterodyne Radiometer for Passive Detection of Chemical Plumes. UTHAM BALACHANDRAN (University of Illinois at Urbana Champaign Champaign, IL 61820) SASAN BAKHTIARI (Argonne National Laboratory, Argonne, IL, 60439)

A radiometric sensor is a passive instrument which detects electromagnetic radiation given off by various agents. Since the radiometer is a passive instrument, it does not need to transmit a signal for detection. The instrument sensitivity and ability to detect sources from large distances compared to optical methods makes this technology ideal for various applications including remote sensing and profiling of the atmosphere as well as weather and humidity measurements. In this study, however, the focus is the radiometer's ability to detect hot chemical plumes at distances of several hundred meters and greater. The Friis Transmission Equation leads us to expect that as the distance increases, the signal will drop at 1/R² with R being the distance between the transmitter and receiver. Setting up the experimental system was a multi-step procedure, requiring calibration and alignment prior to detection of the plumes. The system output needed to be temperature calibrated so that it is best tuned on the desired source. A 150 GHz millimeter-wave beacon was used at various distances to align the radiometer's antenna. The detected signal from the plume was split into sixteen channels, allowing for a more precise observation at each part of the frequency band. To better characterize the system, several measurements were made in order to fit the data to a 1/R² curve. In these experiments, the signal did not appear to drop as rapidly as the equation indicates. This was likely caused by variables such as antenna gain and directivity that were not taken into account in our simplified equation. Although there are aspects of this technology such as the design of high-frequency solid-state devices and signal processing techniques that can be further improved, such systems are expected to make major contributions in the area of remote chemical sensing.

Water-Gas Shift Catalyst Development. GINA FAZIO (University of Illinois at Urbana Champaign Urbana-Champaign, IL 61820) THEODORE KRAUSE (Argonne National Laboratory, Argonne, IL, 60439)

The reforming of infrastructure fuels such as natural gas, liquefied petroleum gas, gasoline, or diesel is one option for producing a hydrogen-rich gas, termed reformate, for fueling fuel cells. In addition to H2, reformate contains other compounds such as carbon dioxide, carbon monoxide, nitrogen, and water. For use with polymer electrolyte fuel cells, reformate must undergo additional process steps to reduce the CO concentration because CO poisons the Pt anode catalyst. The water-gas shift (WGS) reaction is one of the process steps used in most fuel processing schemes to reduce the bulk of the CO concentration. In the WGS reaction, CO and H2O react to produce CO2 and H2 in the presence of a catalyst. Two important criteria for the catalyst are that it enhances the WGS reaction rate and that it does not promote side reactions, such as the methanation reaction (CO + H2) which produces methane and consumes H2. Certain metals such as ruthenium are very active for both the WGS and methanation reactions. The objective of this project is to develop new catalysts based on ruthenium that are highly active for the WGS reaction but do not produce methane. Our approach is to alloy ruthenium or cobalt with a second metal with the aim of reducing or eliminating the methanation reaction while not affecting the WGS reaction. Nineteen different catalyst formulations were prepared by incipient wetness, co-impregnation, or deposition-precipitation. The catalysts were tested in a microreactor system to determine their activities for the WGS and methanation reactions and to determine their long-term durability. Most of the formulations tested showed moderate to high CO conversion, and all produced methane. The best performing catalyst was a Ru-Sn catalyst which displayed the highest CO conversion and the lowest methanation formation.