Two methoxy fuels, dimethoxymethane (DMM) and trimethoxymethane (TMM), were characterized in terms of stability in aqueous solutions and electro-oxidation. TMM was unstable in water even at room temperature, whereas DMM was stable except in an acidic electrolyte or at elevated temperatures. The temperature dependence of the electrochemical oxidation of DMM at Pt and PtRu electrodes was investigated by hydrodynamic voltammetry using a thin-layer flow cell. DMM itself was electrochemically inactive, but a noticeable oxidation current was observed after hydrolysis into methanol and formaldehyde. The oxidation current and the onset potential for the oxidation were comparable to those of methanol in the temperature region from 17 to 120degreesC. (C) 2004 The Electrochemical Society.