Scholarly Communications Project

Document Type:Dissertation
Name:Todd P. St. Clair
Email address:tstclair@vt.edu
URN:1998/00733
Title:Characterization and Reactivity of Mo2C
Degree:Doctor of Philosophy
Department:Chemical Engineering
Committee Chair: David F. Cox
Chair's email:dfcox@vt.edu
Committee Members:S. Ted Oyama, Co-chair
John G. Dillard
Brian E. Hanson
Michael F. Hochella
Keywords:single crystal molybdenum carbide, thiophene desulfurization
Date of defense:June 4, 1998
Availability:Release the entire work for Virginia Tech access only.
After one year release worldwide only with written permission of the student and the advisory committee chair.

Abstract:

Two types of Mo2C have been investigated: polycrystalline beta-Mo2C and single crystal alpha-Mo2C. The beta-Mo2C material was synthesized via a temperature-programmed method, and then characterized using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), CO chemisorption, and N2 physisorption. The catalytic activity of the beta-Mo2C was tested for cumene hydrogenation under high pressure conditions, and the effect of sulfur and oxygen poisons on cumene hydrogenation was also investigated. As a complement to the work done on polycrystalline beta-Mo2C, UHV studies of single crystal alpha-Mo2C were undertaken to provide fundamental information about a well-characterized Mo2C surface. The (0001) surface of alpha-Mo2C was investigated using XPS and low energy electron diffraction (LEED). It was found that an ion-bombarded surface could be prepared as either Mo-terminated or C-terminated by choosing either low annealing temperatures (~1000 K) or high annealing temperatures (~1500 K), respectively. CO and O2 adsorption was also studied on alpha-Mo2C (0001) using thermal desorption spectroscopy (TDS), XPS, Auger electron spectroscopy (AES), and LEED. Finally, thiophene adsorption was investigated on alpha-Mo2C (0001).

List of Attached Files

diss.PDF

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