Year of Publication

2015

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Arts and Sciences

Department

Chemistry

First Advisor

Dr. Jack Selegue

Second Advisor

Dr. Burtron H. Davis

Abstract

The Fischer-Tropsch process, discovered in the early to mid-1920s, still has researchers disputing the C1 monomer, and the rate-determining step. A tremendous amount of work, over the years, has focused on how hydrogen plays a role in the pseudo-polymerization of chain initiation and propagation, in an attempt to reveal the mechanism. These investigations attempted to elucidate the debated issues through studying the kinetic isotopic effect (KIE) for CO hydrogenation by switching the syngas from CO/H2 to CO/D2 during a steady-state period. Applying this switching step could result in a deviation in the rate of CO hydrogenation, indicating a KIE. However, results for this process were still not fully clear as not all observations agreed, which indicated that the KIE could be the result of a combination of how hydrogen interacts thermodynamically (adsorption) and kinetically (CO hydrogenation) in FT synthesis. That is, hydrogen must be activated through dissociative adsorption before interacting in CO hydrogenation. Thus, the primary emphasis of this dissertation is to focus upon how the dissociatively adsorbed hydrogen and deuterium atoms are apportioned upon the surface of an active Fischer-Tropsch Catalyst, pinpointing whether competitive adsorption is muddling the KIE for CO hydrogenation.

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