The combination of pulsed positive streamer corona discharge with a platinum-rhodium catalyst was investigated for removal of toluene, acetonitrile. and nitrogen oxides. The reactor used consisted of two parallel disks made from reticulated vitreous carbon, with the downstream disk coated with platinum and rhodium. Removal of contaminants was measured with and without plasma over a range of temperatures, and several interesting phenomena were observed which differed between the three species. Results indicate that the catalyst is capable of both reduction of nitrogen oxides and oxidation of hydrocarbons. In addition, the combination of the active catalyst with the plasma discharge was found to either enhance or interrupt catalyst activity depending on which contaminant was considered and the catalyst temperature. (C) 2003 Elsevier B.V. All rights reserved.