Catalytic combustion of hydrocarbon and oxygenated fuels has the potential to provide an alternative power source for portable electronic devices. Our previous studies have demonstrated sustained catalytic combustion for a variety of fuels using multi-channel cordierite substrates. In particular, methanol-air mixtures catalyzed by platinum nanoparticles yielded room-temperature self-ignition and stable combustion. The present work explores a stacked-reactor design of a microcombustion-thermoelectric coupled device that marries thermal management strategies with catalytic combustion. Synthesized platinum nanoparticles ( 8 nm) were deposited on rectangular cordierite substrate cartridges with 800 m wide channels. A custom-designed copper-aluminum reactor was used to host the catalytic cartridges. A near-stoichiometric mixture of methanol-air at 8000 mL/min air flow rate produced 62 C temperature difference across thermoelectric generators. Material analysis demonstrated a non-uniform restructuring of catalyst material across the substrate. A parametric study of catalyst loading and air flow mapped the optimal operational range of the device. While a relatively low power output of 490 mW was measured, a theoretical power potential of 1400 mW was estimated. The results confirm the unique advantages of multi-channel catalytic cartridges and guide future developments in the application of nanocatalytic microcombustion for portable power sources.