The decomposition of fluorocarbons (1%) in Ar was investigated using a surface discharge-type plasma reactor. To enhance the effectiveness of plasma chemical processing, we investigated the effects of catalysts and additives. The removal rate increased when the plasma reactor was packed with TiO2 pellets as a catalyst. The catalytic effect seems to be derived from the direct activation of the TiO2 surface by the plasma discharge, because significant UV emission and temperature increase were not observed in the plasma reactor. The removal rate was also enhanced when water vapor, oxygen, or hydrogen was added to the reactant. In addition, the presence of TiO2 or the additional gases or both depressed byproduct formation. Analysis of the reaction products suggested that the catalysts and additives enhanced the process by preventing the recombination of decomposed fragments. (C) 2004 Elsevier B.V. All rights reserved.