To improve the performance of methane steam reforming as an endothermic reaction, the heat transfer efficiency from a heat source to a catalyst is a much more important factor than the reaction activity of catalyst itself on an industrial scale. In this context, microchannel reactors with combustion reaction (comb) blocks and reforming reaction (reform) blocks assembled by turns attract great attention due to their enhanced heat transfer rate. However, the even heat transfer to a catalyst bed is still a challenging topic. In this study, we improved the heat transfer efficiency of microchannel methane steam reformers by using porous-membrane-type catalysts and shifting a combustion point onto the top of the catalysts. As a result, methane conversion (conv) has increased by 14.7% at the same supply rate of fuel. Surprisingly, 1 Nm(3) h (1) of hydrogen has been produced using just 0.58 L (H: 2.9 cm, W: 20cm, L: 10 cm) of reactors. In addition, the long-term stability of our microchannel reformers was verified by methane reforming tests for 500 h. Therefore, our microchannel reactors are expected to be more suitable for distributed power generation based on fuel cells. (C) 2016 Elsevier Ltd. All rights reserved.