Meso- and Microporous Metal–Organic Frameworks for Efficient Photo-Oxidation of Benzylamine

The construction of metal–organic frameworks (MOFs) with desirable structures for high-performance photocatalysis is attractive but remains challenging. Here, a hierarchically meso- and microporous sc Cu-MOF-74 was synthesized in supercritical CO 2 ( sc CO 2 )/methanol solution. Compared with the conventional microporous Cu-MOF-74, the meso- and microporous sc Cu-MOF-74 has more exposed and accessible Lewis acid sites derived from the missing-linker defects. The unique structure endows sc Cu-MOF-74 with superior molecular accessibility, enhanced separation, and transfer efficiency of photogenerated charges. High catalytic activity and reusability can be achieved in photo-oxidative coupling of amines, reaching a maximum N-benzylbenzaldimine yield rate of 4.80 mmol g −1 h −1 under mild conditions, that is, air atmosphere and room temperature. This study provides a new idea for improving the intrinsic photocatalytic activities of MOFs.