Photoreactors manufactured from 3D-printed (photo-) catalytic materials

This study demonstrates the successful fabrication of 3D-printed, photoactive reactor components utilizing a TiO₂-polypropylene composite filament. The reactor components were employed in the photocatalytic reduction of nitrobenzene and the photocatalyzed synthesis of quinaldine. The reactor inserts were subjected to hydrodynamic and reactive characterization. Furthermore, the viability of employing a solid acid as an alternative to a homogeneous acid catalyst was demonstrated for the photocatalytic synthesis of quinaldine. It was determined that the immobilization of the solid acid not only affects the activity but also the selectivity of the reaction. The immobilization of catalysts obviates the necessity for downstream separation and allows for the modification of reactor designs to achieve optimal reaction performance. The selected rapid prototyping approach facilitated the acceleration of development cycles, and the use of multiple parts comprising different chemically active components enabled the tailoring of (photo)chemical reactors, ultimately paving the way for the development of multi-functional reactors for cascade reactions with high performance and selectivities.