This work reports product composition and kinetics of the catalytic decomposition of methylal (dimethoxymethane, C3H8O2), which is a good hydrogen vector. To the best of our knowledge, this is the first report on methylal reforming by decomposition over supported metal catalysts for fueling an internal combustion engine (ICE) while using the hot exhaust gases to heat the reactor. The decomposition activities of commercial Pt/Al2O3, Ni/Al2O3, and laboratory-synthesized Rh/Al2O3 were investigated. While the activities of Pt and Ni catalysts were promising, Rh exhibits poor activity. Pt catalyst exhibits appreciable methylal conversion and yields primarily a mixture of H2, CO, and DME above 300 °C. Ni produces a mixture of H2, CO, and methane. Isothermal studies revealed that both catalysts undergo deactivation evident by an initial decline in H2 and CO production rates while DME production was stable. Coke deposition was observed on both catalysts, but the TPO revealed 5 times more coke on Ni catalysts than on Pt at 300 °C. Since the deposited carbon is reactive in nature, a simple regeneration step at temperatures around 400 °C is sufficient to restore the activity. Based on the experimental results, a model in the form of two consecutive reactions, decomposition to methanol followed by reforming to DME + H2 + CO, was developed for Pt, and the rate constants and activation energies were determined.