In this work, carbon-supported CoSe2 is used as a Pt-free cathode catalyst in a passive, air-breathing, alkaline anion exchange membrane μ-direct methanol fuel cell (AEM-μDMFC). The obtained results demonstrate the improvement in the performance, when the device is operated at high fuel concentrations, if the proposed cathode catalyst is used instead of the standard Pt/C catalyst, due to the better tolerance to methanol crossover even in alkaline medium. This result reinforces the suitability of AEM-DMFC's as a promising option for mobile devices powering.