Ethanol steam reforming was studied over a supported Ir/CeO 2 catalyst in a micro-channel structured reactor. The catalyst coating was deposited on the channel walls and showed a remarkably high homogeneity and an excellent adherence to the stainless steel substrate, leading to stable performance during long-term runs. Hydrogen yields exceeding 40 L H2 g cat −1 h −1 were achieved during testing with partial ethanol conversion of 65% and a residence time in the order of a few milliseconds. This hydrogen productivity was found significantly higher than in a comparable conventional fixed-bed reactor hence being extremely promising for hydrogen production in micro fuel cell applications.