This paper proposes a novel structured foam microreactor with controllable gas and liquid flow paths; in this microreactor, the liquid phase flows through a structured foam bed, and the gas phase flows through gas paths on both sides of the foam bed. A hydrodynamics analysis indicated that the proposed design ensured not only better residence time distribution and a longer residence time, but also uniform phase distribution and a stable gas–liquid interface. Accordingly, inefficient catalysts utilization and mass transport caused by the gas channeling in conventional foam-based microreactors was avoided. The results showed that the newly-developed microreactor exhibited higher nitrobenzene conversion because of the aforementioned merits. This study not only serves as a guideline for the optimization of the proposed microreactor, but also provides a new avenue for the design of multiphase catalytic reactors.