Synthesis of CNTs@POP-Salen Core-Shell Nanostructures for Catalytic Epoxides Hydration

Microporous polymers have been considered as promising heterogeneous catalysts for versatile chemical transformations. However, the mass diffusion barriers through the microporous network still remains a big hindrance. Herein, an efficient and versatile strategy for shortening the mass diffusion pathway through microporous polymer was reported by constructing a CNTs@POP-salen core-shell nanostructure. CNTs@POP-Co(salen) could efficiently catalyze the epoxide hydration reaction at H2O/epoxides ratio as low as 2, demonstrating the efficient cooperation of Co(salen) integrated in the polymer network. CNTs@POP-Co(salen) showed much higher activity than bulk polymer in propylene oxide (PO) hydration reaction (TOF: 3150 versus 1470 h(-1)) due to the shortened diffusion pathway, which was further confirmed by adsorption experiment using phenol as probe molecule. Our primary results demonstrated the advantages of core-shell nanostructures to improve the catalytic activity of microporous polymers by enhancing the mass diffusion during the catalytic process.