ABSTRACT CTS-9509580 The objective of this effort is to relate the energetics of carbon-chlorine bond dissociation in hydrodechlorination to catalyst performance under industrially relevant conditions. This is a collaborative effort combining surface-science measurements of reaction kinetics on palladium (111), done at Carnegie Mellon University, with reaction studies at atmospheric pressure catalyzed by supported palladium particles, performed at the University of Pittsburgh. A common set of selectively fluorinated chloromethanes and chloroethanes serves to link the surface-science and catalytic investigations. Both studies measure heats of adsorption, apparent activation energies, intrinsic activation energies, and rate constants. Linear free-energy relationships are used to determine whether carbon-chlorine bond dissociation is homolytic or heterolytic, and predict the effects of modifiers. This is a study of the conversion of chlorofluorocarbons (CFCs) into hydroflourocarbons (HFCs). The results are also applicable to the destruction of chlorocarbons at low temperature. Thus the study has direct impact both on the manufacture of refrigerants and blowing agents and on the environmental management of cleaning agents.
