INVESTIGATIONS OF THE FISCHER-TROPSCH SYNTHESIS AND THE HYDROGENOLYSIS OF ALKANES (CATALYSIS, CARBON MONOXIDE, HETEROGENEOUS)

This dissertation is divided into two parts. The first part involves the mechanism of the Fischer-Tropsch synthesis, a heterogeneous catalytic reaction which synthesizes linear hydrocarbons from carbon monoxide and hydrogen. The second part involves an investigation of the mechanism of the hydrogenolysis of linear, cyclic, and branched hydrocarbons, a catalytic reaction that is the basis for the catalytic reforming of petroleum.; Formaldehyde, methanol, acetaldehyde, and ethanol are decomposed with or without hydrogen over Fischer-Tropsch catalysts. The products and product distributions of these decompositions correlate with those of a typical Fischer-Tropsch synthesis. The mechanism of hydrocarbon product formation directly involves the oxygenate reactant and does not involve oxygenate decomposition to carbon monooxide and hydrogen.; The hydrogenolysis of n-octane and 1-octene in the presence of hydrogen over heterogeneous cobalt, ruthenium, and nickel catalysts produces product distributions consistent with a mechanism in which C-C bond breaking in hydrogenolysis is the reverse of C-C bond formation in the Fischer-Tropsch synthesis. This mechanism is in contrast to the currently accepted mechanism of hydrogenolysis which involves extensive dehydrogenation of adsorbed hydrocarbon fragments. Using this mechanism, a mathematical model is developed which predicts product distributions for the hydrogenolysis of any linear hydrocarbon.; The hydrogenolysis of cyclooctane, cyclohexane, neohexene, and neohexane in the presence of hydrogen over the same catalysts produces product distributions consistent with the mechanism established for linear hydrocarbon hydrogenolysis and are predicted by the mathematical model.