A Modular Tubular Flow System with Replaceable Photocatalyst Membranes for Scalable Coupling and Hydrogenation

Heterogeneous photocatalysis is effective for the selective synthesis of value‐added chemicals at lab‐scale, yet falls short of requirements for mass production (low cost and user friendliness). Here we report the design and fabrication of a modular tubular flow system embedded with replaceable photocatalyst membranes for scalable photocatalytic C−C, C−N homocoupling and hydrogenation reactions, which can be operated in either circular and continuous flow mode with high performance. The photocatalyst membranes almost fully occupy the volume of the reactor, thus enabling optimal absorption of the incident light. Additionally, the porous structured photocatalyst membranes facilitate the mass transfer of the reactants to efficiently use the active sites, resulting in 0 th ‐order reaction kinetics and a high space‐time yield compared to the batch reaction system at practical application levels and prolonged reaction times.