Interfacial coupling between noble metal nanoparticles and metal-organic frameworks for enhanced catalytic activity.

Metal-organic frameworks (MOFs) have great potential to become innovative heterogeneous supports for immobilizing catalytically active noble metal nanoparticles (NPs). However, unlike metal oxide supports, the interfacial interactions between noble metal NPs and MOFs are currently neglected, thus dramatically diminishing the advantage of MOFs as supports. Herein, ZIFs(Co/Zn)@M (M = Pd, Pt or Au) nanocomposites with well-defined interfaces are synthesized and used as catalysts in gas-phase CO oxidation and liquid-phase C6H5CHO oxidation. Notably, in both reactions, ZIF-67(Co)@M samples exhibit better catalytic activity than ZIF-8(Zn)@M samples, and moreover, the catalytic activity of ZIFs@Pd is higher than that of ZIFs@Pt and ZIFs@Au samples. Experimental and theoretical results reveal that the enhanced catalytic activity originates from the interfacial electron transfer from ZIFs to noble metal NPs as well as the coupling between d band of noble metal in NPs and metal node in ZIFs.