The catalytic activity in CH4 oxidation over a La0.8Ce0.2MnO3 perovskite as a model reaction is investigated under dielectric and conventional heating conditions. As these materials are both microwave sensitive and catalytically active, they may be applied as coating material for ceramic soot filters for the reduction of soot emission from diesel engines. Dielectric heating is shown to result in a much higher CH4 conversion and a higher resistance to SO2 Poisoning. We propose that local hot spots on the catalytic surface explain the increased activity toward CH4 conversion. The catalytic activity in SO2 is largely maintained, as pore blockage by sulfates, as experienced in conventional heating, is counteracted. (C) 2003 Elsevier Inc. All rights reserved.