Universal, Time-Cost-Effective, and Inside-Out Strategy for Synthesis of Plant-Based Flow Catalysis Microreactors

The utilization of plant-based flow catalytic microreactors has been increasingly gaining traction in the fields of water treatment, energy generation, and biotechnological science due to their inherent channel structures, renewable properties, and environmentally friendly nature. The conventional outside-in strategy for synthesizing plant-based monolithic microreactors typically entails prolonged hydrothermal modification, extensive chemical usage, or energy-intensive equipment. The present study presents a universal inside-out strategy for the rapid synthesis of monolithic catalytic microreactors derived from plant materials. This approach enables the direct formation of catalytic metal nanoparticles within specific plant microchannels through regioselective deposition, resulting in reduced chemical usage and an accelerated process. Moreover, this method effectively minimizes the required catalyst dosage. In this process, the plant monolith's aligned, narrow, and accessible channels provided a higher contact area, shorter diffusion path, and abundant oxygen-containing functional groups for rapid transformation of metal salt precursors into catalytic metal nanoparticles with excellent dispersion. The inside-out strategy can be extended to various plant-based monoliths and diverse metal/metal oxide/MOF materials within the plant monolith, thereby offering a facile, time- and cost-effective universal approach for skillfully designing plant-based flow microreactors for a wide range of applications.