Basic and Applied Sciences Posters

BASIC AND APPLIED SCIENCES
• Publications
• Posters
• Staff
• Argonne Coin Cell NMR/MRI Imager
• Aluminum Nanoparticles
• Fluid Catalysis Program
• Nanoporous Catalyst Membrane
• Toroid Cavity Imagers and Detectors
• NOx Catalyst

Characterization of Materials and Structures Using Raman Microspectroscopy

Victor A. Maroni

This poster will illustrate how workers in the Chemical Engineering Division have used Raman microspectroscopy and imaging Raman microscopy to examine materials and structures that are relevant to a wide variety of technological issues in the field of energy production and distribution. Examples of Raman results that are pertinent to high-critical-temperature superconductivity, metal dusting (by carbon) in low oxygen pressure environments, and micro-electro-mechanical device technology will be included in the poster. Arrays of Raman spectra recorded on moving samples and spatial images of individual chemical phases in multiphase structures will be presented and interpreted. The unique information provided by the Raman measurements will be compared and contrasted with results obtained using other types of characterization tools. In particular, comparisons will be made with results from x-ray diffraction as well as from optical and electron microscopy examinations of the same (or similar) samples.

This research is supported by The U.S. Department of Energy (DOE), Office of Electric Transmission and Distribution; DOE Office of Industrial Technologies.

Chemical and Spatial Analyses of Chemical Systems: Toroid Cavity NMR Imagers

Rex E. Gerald II et al.

We investigate fundamental physicochemical problems in chemically transforming systems relevant to our nation's long-term energy needs. Several areas of active research in our group include in situ investigations of rechargeable electrochemical cells, nondestructive analyses of stored radioactive materials, and dynamic analyses of materials under stress. A common tool used in our investigations is the toroid cavity imager, a nuclear magnetic resonance (NMR) device invented and developed in our laboratory. Toroid cavity NMR imagers are simple, robust, and scalable detectors that are capable of elemental and chemical analyses with micrometer spatial resolution of materials in the fluid and solid phases. Our novel device address fundamental limitations of NMR detectors in applications to chemical problems in catalysis, nuclear waste, and energy storage. Limitations inherent in commercially available NMR detectors include detector operation restricted to modest pressures, low detector sensitivity, and limited detector scalability. Three applications of toroid cavity NMR imagers in our basic science programs will be presented to illustrate the wide range of analytical capabilities of this device.

This work is supported by the U.S. Department of Energy, Division of Chemical Sciences, Office of Basic Energy Sciences.

Reaction Pathways in Catalytic CO Hydrogenation

Jerome W. Rathke, Robert J. Klingler, Michael J. Chen, Rex E. Gerald II, Jody L. Rodgers, and Davi. S. Hacker

Catalytic carbon monoxide hydrogenation processes (e.g., the Fischer-Tropsch Process) are of current interest due to the need to find methods of converting natural gas to liquid fuels suitable for transport. We recently tested the use of a high-pressure NMR probe on the cobalt carbonyl catalyzed CO hydrogenation in supercritical carbon monoxide medium for the first time. A single-phase homogeneous supercritical system containing catalyst and reactant gases was utilized to avoid gas-liquid mixing problems that might otherwise interfere with kinetic studies in an unstirred NMR pressure vessel using conventional liquid media. Also, and of key importance, the supercritical fluid behaves as a gas-like reaction medium that is highly amenable to planned theoretical calculations. Separate experiments established that the homologation of methanol, the pathway for production of higher alcohols under CO hydrogenation conditions in polar solvents, did not occur to a measurable extent in the nonpolar supercritical CO medium used here.

This research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences.

Bifunctional Catalysts for the Selective Catalytic Reduction of NOx wit. Hydrocarbons

Christopher L. Marshall, Michael K. Neylon, and Mario J. Castagnola

Novel bifunctional catalysts combining two active phases, typically Cu-ZSM-5 and a modifier, were prepared and tested for the selective catalytic reduction of nitrogen oxides using propylene in order to overcome the hindering effects of water typically seen for single-phase catalysts such as Cu-ZSM-5. Chemical characterization by temperature-programmed reactions, DRIFTS and x-ray absorption spectroscopy indicated strong interaction between the two phases, primarily producing materials that exhibited lower reduction temperatures. Two improvements in NOx reduction activity were seen for these catalysts compared with Cu-ZSM-5: a lower temperature of maximum NOx conversion activity (as low at 250°C) and an enhancement of activity when water was present in the system. The use of a second phase provides a way to further tailor the properties of the catalyst in order to achieve the mechanistic conditions necessary to maximize NOx remediation.

This research is funded by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy and Office of Science.