Significant hydrogen production (0.33 mol% in products) from H2O splitting by atmospheric dielectric barrier discharges has been achieved with tubular PACT reactors at room temperature. Effects of different experimental parameters, such as different metal (either Ni, Pd, Rh, or Au) coated inner electrodes, types and lengths of outer metal (either Al or Cu) electrodes, grounding states of the inner and outer electrodes, AC peak voltages applied on the reactor, and the flow rate of the feed (2.3 mol% in Ar), have been systematically studied. The water splitting activity varies when the type of metal-coated inner electrodes, peak voltage, the length of outer electrode, and the flow rate of the feed change, but does not depend on the types of outer metal electrodes and the grounding states of the inner and outer electrodes.