Self-coupling reactions of terminal alkynes catalyzed by nanorod-like metalloporphyrin organic frameworks encapsulated with copper nanoparticles: Synergistic catalytic effects of dual copper structures

Abstract

By encapsulating metal nanoparticles (NPs), the synergistic effect between the metalloporphyrins and the metal nanoparticles in metalloporphyrin organic frameworks (P-MOFs) can boost its catalytic performance. The self-coupling reaction of terminal alkynes is a kind of important organic reaction and can take place with the aid of the catalyst. A nanorod-like metal-organic skeleton PCN-222(Cu) with carboxy porphyrins as ligands was synthesized as the precursor. By a double-solvent approach, the composite catalysts with varying copper nano-loadings in PCN-222(Cu) pores were obtained. Among them, 1.9 wt% of Cu NPs in Cu@PCN-222(Cu) has excellent catalytic activity and stability for the self-coupling reaction of terminal alkynes. PCN-222(Cu) can stabilize the Cu NPs, control the size selectivity and crystal form. The copper porphyrins and Cu NPs in Cu@PCN-222(Cu) both serve as the catalytic active sites. This strategy, which using porphyrin-structured MOFs to construct dual active sites with the same element, has promising applications in MOFs catalysis.