Oxidation of propane over various cathodes of the H-2-O-2 cell system was studied in the gas phase at 298 K. The cathode prepared from vapor-growing-carbon-fiber (VGCF) supported VO(acac)(2) and Pd-black was most active for the oxidation of propane. Products were acetone, acetic acid and CO2. The (Pd-black + VGCF) cathode and the (VO(acac)(2)/VGCF) cathode were not good for the oxidation. Co-addition of Pd-black and VO(acac)(2) to VGCF remark-ably enhanced the formation rate of products and increased the selectivity to acetone. This strong synergism of Pd and VO(acac)(2) over VGCF was studied in detail. The active oxygen species generated on the (Pd-black + VO(acac)(2)/VGCF) cathode oxidized ethane to acetic acid at 298 K, but a (race amount of CO2 was the only product in the oxidation of methane.