Pd Nanoclusters Supported by Amine-Functionalized Covalent Organic Frameworks for Benzyl Alcohol Oxidation

A major impediment of the incorporation of extra functional groups on skeletons of covalent organic frameworks (COFs) is the long-ordered microporosity over their networks. This problem has delayed the practical applications of these highly porous materials for chemical sensing, CO2 capture, and heterogeneous catalysis. In this work, we demonstrated a facile method named the nonstoichiometric synthon strategy to introduce functional groups onto the network of the COFs for further metallic nanoparticle confinement. By simply adjusting the ratio of primitive synthons, we can deliberately decorate the interior pores of the resultant COF materials with amine groups from the excess synthon fragments, while maintaining the structure of the parent COF. Benefiting from the excess dangling amine groups on the network, these COFs are readily available as catalytic support for the confinement of ultrasmall metallic Pd nanoclusters and further used for the benzyl alcohol oxidation reaction.