The steam reforming of methane on a rhodium/alumina based multifunctional microreactor is simulated using fundamental chemical kinetics in a pseudo-two-dimensional microreactor model. The microreactor consists of parallel catalytic plates, whereby catalytic combustion and reforming take place oil opposite sides of a wall. Heat exchange happens through the wall. It is shown that reforming can happen in millisecond or lower contact times and proper balancing of flow, rates can give high conversions, reasonably high temperatures, and high yield to syngas. It is found that tuning catalyst surface area and internal and external mass and heat transfer through reactor sizing can lead to further process intensification.