In the current study we investigate the combined operation of a dielectric barrier discharge and an alpha-alumina supported Ni catalyst in the partial oxidation of methane. In order to separate the effects of plasma activation from catalytic processes, the study includes both purely catalytic and plasma-activated operation of the reactor. Whereas the catalyst alone is only active above 300 degreesC, plasma induced partial oxidation of methane is observed in the entire temperature range investigated (100-400 degreesC). By comparing the reaction over the Ni catalyst in different oxidation states with the catalyst support only, conclusions are drawn regarding surface and gas phase processes. (C) 2003 Elsevier B.V. All rights reserved.