Ultrafine Pd Nanoparticles Encapsulated in Mesoporous TiO₂ Region Selectively Confined in Bamboo Microchannels: An Ultrastable Continuous‐Flow Catalytic Hydrogenation Microreactor

Plant-based flow microreactors with natural channel structures, renewable properties, and environmental friendliness have increasingly gained popularity in heterogeneous catalysis. However, firmly immobilizing the catalysts simultaneously ease adaptability, maintaining great effectivity long-term stability, is still a fundamental challenge. Herein, highly efficient ultrastable bamboo-based catalytic microreactor (CMR) containing mesoporous TiO2 (M-TiO2)-encapsulating ultrafine Pd nanoparticles (NPs) constructed for continuous-flow hydrogenation of nitroaromatics. The fabrication Pd-TiO2 required bamboo microchannels (Pd-TiO2/B CMR) mainly involves two-step region-selective synthetic strategy ultra-low chemical usage, fast preparation, low catalyst loading (0.007 wt%). M-TiO2 films: 1) provide abundant oxygen vacancies enough open cavities to facilitate growth NPs; 2) improve dispersion reduce particle size; 3) allow diffusion reactants, 4) induce strong metal-support interactions enhanced activity stability. optimized Pd-TiO2/B CMR demonstrates high efficiency (>97%) excellent stability (1,000 h) nitroaniline, even under intermittent operation (12 h on/12 off five cycles) or real aqueous matrix (>200 h), making it promising candidate Pd-catalyzed hydrogenation.