(672a) 3D-Printed Capillary Force Trap Reactors (CFTRS) for Multiphase Catalysis Flow Chemistry

In this work, we introduce a ‘Capillary Force Trap Reactor’ (CFTR) for performing industry relevant multiphase flow reactions. By leveraging additive manufacturing (AM) or 3D printing methods and small-scale fluid physics, the CFTR enables intensified catalytic reactions such as hydrogenations with facile catalyst replenishment. The central concept of this reactor paradigm is the temporary trapping of colloidal solutions of metallic nanoparticle catalysts via capillary forces within a reactor through which reactant gases and liquids flow. We discuss the design, fabrication, operation, and analysis of such reactors, along with demonstrations of online catalyst recovery and replenishment. We start by establishing the operating limits of the capillary force traps in a CFTR with a simple proof-of-concept design. We then implement a model reaction to evaluate the performance of the CFTR, demonstrating complete conversion of hydrogenation of 1-hexene to n-hexane catalyzed by polyvinylpyrrolidone (PVP) stabilized rhodium nanoparticle (RhNP) catalysts suspended in water. Lastly, we show a facile way of replenishing used catalyst to maintain performance throughout the five-hour operating period of the reactor, and discuss tuning reactor performance when catalyst deactivation occurs. This work illustrates the possibility of harnessing 3D printing for more sophisticated novel capillary flow trap designs, and opens up new routes for ‘designer’ flow reactors for multiphase catalytic reactions.