Encapsulating Ultrastable Metal Nanoparticles within Reticular Schiff Base Nanospaces for Enhanced Catalytic Performance

Controllable fabrication of ultrasmall, highly dispersed and functionalized metal nanoparticles (MNPs) is crucial for industrially important applications. Here, we demonstrate a metal-Schiff base template approach that allows confined growth of a broad spectrum of MNPs within the reticular Schiff base nanospaces with ultrasmall size (<2 nm), high dispersibility, and excellent stability. Owing to the unusual synergy between the Schiff base binding sites and the MNPs, the strong confinement within open cavities, as well as the distinct small size and “clean” surface of MNPs, the as-prepared MNPs exhibit highly enhanced catalytic activity and durability in the methanolysis of ammonia borane to generate hydrogen in organic media. This heterogeneous catalyst affords a turnover frequency (TOF) value of 177 min−1 at 303 K.