Soluble porous carbon cage-encapsulated highly active metal nanoparticle catalysts

Abstract

Homogenization of heterogeneous catalysts by encapsulating metal nanoparticles inside soluble cages is of great interest. Previously organic cages have been used to encapsulate metal nanoparticles, but the limited stabilities and poor water solubilities restrict their applications in conventional catalysis. Here, we report a silica (SiO₂)-shelled metal–organic framework (MOF) pyrolysis approach that enables the encapsulation of Ru nanoparticles (RuNPs) into soluble porous carbon cages (SPCCs). By encapsulating RuNPs into nanoscale ZIF-8, covering compact SiO₂ layers and performing controllable pyrolysis, RuNPs are well encapsulated inside SPCCs, showing high solubilities and excellent dispersibilities in solvents (water and alcohol), exhibiting excellent O₂ and H₂ generation rates, with turnover frequencies (TOF) up to 1010 and 1094 min⁻¹ at 303 K, from hydrogen peroxide and from ammonia borane hydrolysis, respectively, representing the top level among the state-of-the-art catalysts. Moreover, owing to the stable structure and the effective confinement of SPCCs, the as-prepared catalysts possess excellent stability and durability.