Spectroscopic and Microscopic Characterization of Graphite
EMSL Project ID
18890
Abstract
Majority of the energy requirement of many industrial processes is met through utilization of reactions of carbon and carbonaceous materials with oxygen, steam, carbon dioxide and hydrogen. The mechanisms of the gas reactions of carbon/graphite are not well established and the properties of carbonaceous materials have not been studied extensively in the past. This is primarily due to the lack of experimental techniques that can be used for the detailed characterization of these materials. Retarding the gas-carbon reaction would be beneficial to many industrial processes. For example, when carbon is used as an electrode material, it is desirable to have minimum reaction of the carbon with the carbon dioxide produced by the reduction of the ore or with the ambient atmosphere. In this research, we plan to carry out X-ray photoemission spectroscopy (XPS) depth profiling of several oxidized graphite samples in order to study the different phases of oxidized graphite. This research will also provide us with a better understanding of mass transport of the reacting gas from the exterior surface to an active site beneath the surface. The second part of this research will involve characterization of a series of graphite materials including nuclear grade graphites in order to obtain improved understanding of molecular level structural properties and interfacial phenomena in these materials. The quality of nuclear graphite is gauged by physical properties, purity, and irradiation behavior. A graphite grade with large crystallites is thought to better "anneal out" the damage caused by irradiation. Graphite with very small crystallites tends to develop porosity at a slower rate than one with comparatively large crystallites. It is therefore necessary to have an optimum crystallite size that will have desirable irradiation behavior. We would like to study the structure of nuclear graphite samples, specifically, the differences in structure between the binder phase (graphite derived from pitch precursor) and the filler phase (graphite derived from coke precusor) using microscopic and spectroscopic techniques. High quality control is essentional for production of these materials to ensure the consistency (isotropy) of the material throughout. Our proposed work involves the study of structural crystallography of PCEA and BAN graphite using transmission electron microscopy (TEM) and Rutherford Back Scattering Spectroscopy (RBS).
GrafTech International Inc. is the world leader in the manufacture of carbon and graphite products with facilities in four continents and approximately 4000 employees. The research and development center of GrafTech is one of the premier technology centers in the world for the study and application of carbon and graphite. EMSL offers a unique combination of microscopic and spectroscopic facilities that is not available elsewhere. This proposed research will allow us to study the structure of graphite as well as the reaction mechanisms of oxidation of graphite, which will lead to precise control of catalytic activity and selectivity of several of our manufacturing processes.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2006-07-28
End Date
2007-01-08
Status
Closed
Released Data Link
Team
Principal Investigator