A novel co-flow heat exchanger intended for volumetrically efficient hydrogen production and utilizing catalytic surface combustion to drive endothermic steam reforming occurring in adjacent channels has been investigated experimentally and numerically. A single plate reactor has been developed for studying the complex interactions between H2 or CH4 combustion over a supported Pd catalyst and CH4 steam reforming over a supported Rh catalyst. Experiments have been conducted to determine a stable window of operation for the system and to observe the effects that inlet temperature, steam to carbon ratio, and reforming flow rates have on surface temperatures and reformate composition. The experiments have been used to validate a transient model of the dual channel reactor design employing distinctly different surface chemistries. Modeling results show that reforming can be sustained with adequate conversion to maintain combustion catalyst temperatures within the range where activity of both catalysts is high.