Abstract: | The hydrogenation of chlorofluorocarbons (CFC's, 1,1- dichlorotetrafluoroethane, CCl2F-CF3) was found to be positive 1/2 order in hydrogen pressure over palladium foil while it was zero order in hydrogen pressure
over palladium single crystals regardless of their orientation ((111), (100)). When hydrogen was completely removed from the
gas phase, hydrogenation continued for about 104 turnovers over palladium single crystals which were pre-exposed to hydrogen. Solid state hydrogen, stored in the bulk of
a palladium single crystal, was found to be responsible for the hydrodechlorination of CCl2F-CF3 in the absence of gas phase hydrogen. Lower reaction rates and increased selectivity for overhydrogenation to produce CH3-CF3 indicate that the nature of hydrogenation with solid state hydrogen in palladium is different from hydrogenation with gas
phase hydrogen. The use of solid state hydrogen for various chemical processes instead of gas phase hydrogen has advantages
that are enumerated.
This revised version was published online in July 2006 with corrections to the Cover Date. |