RESUMO
Metal-organic frameworks (MOFs)-supported noble metal nanoparticles (NMNPs) catalysts attract increasing attention due to their high durability and efficiency in catalytic reactions. In this work, Pt nanoparticles are inserted at the designated location inside MIL-100(Fe) to investigate the location-effect of NMNPs inside MOFs on the catalytic reaction. The comparison test on the reduction of p-nitrophenol suggests that the location of the Pt nanoparticles inside MIL-100(Fe) largely influences the catalytic performance and the Pt nanoparticles inside MIL-100(Fe) locate closer to the outer surface of the MIL-100(Fe), providing higher catalytic efficiency. Possible reasons are concluded as the location of the Pt nanoparticles inside MIL-100(Fe) dominates the reactants transport pathway and the loading amount of Pt nanoparticles.
RESUMO
Metal-organic framework (MOF)-based magnetic Pt catalyst Fe3O4@Pt@MIL-100(Fe) core-shell heterostructures were prepared through transforming Fe3O4 into MIL-100(Fe) in benzene-1,3,5-tricarboxylic acid solution along with encapsulating the Pt nanoparticles successively adsorbed onto the surface of the Fe3O4 nanosphere and the continuously forming surfaces of the growing MIL-100(Fe) crystals. This method circumvented the obstacles, controlling the formation of metal nanoparticles (MNPs) inside MOFs or regulating growth of MOFs around the MNPs, for preparing an MNP-MOF composite catalyst. The obtained well-defined Fe3O4@Pt@MIL-100(Fe) core-shell heterostructure was shown promoting catalytic activity on the reduction of 4-nitrophenol due to the synergistic effect between the Pt nanoparticles and the MIL-100(Fe) shell and recycling convenience due to the rapid separation of the Fe3O4 core under an external magnetic field.
