Noble Metal/Metal Organic Frameworks Derivatives For Catalytic Water Splitting And Coupling Reactions

Metal-organic frameworks?MOFs?have been concerned due to their high specific surface areas,rich porous structures and tunable compositions.Recently,they are used as promising self-sacrificing templates or precursors for preparing various derived functional materials.Herein,a series of catalysts were prepared via the facile oxidation,carbonization,phosphorization and sulfurization treatment of a stable zeolitic imidazolate frameworks?ZIFs?materials followed by doping noble metal nanoparticles respectively.Owning to the inherited hierarchical porous structures and the high specific surface area for ZIFs,they display excellent catalytic properties.The detailed contents and results are listed as follows:1.Fabrication of porous Pt-doping heterojunctions by using bimetallic MOF template for photocatalytic hydrogen generationUsing bimetallic ZnCo-ZIF as template,heterojunction photocatalysts,Pt-ZnO-Co₃O₄,Pt-ZnS-CoS and Pt-Zn₃P₂-CoP were succesfully prepared via the facile oxidation,sulfurization,and phosphorization treatment of bimetallic ZnCo-ZIF followed by doping Pt nanoparticles,respectively for photocatalytic hydrogen generation.It was found that the resultant photocatalysts retained the original morphology of the parent ZnCo-ZIF,and the resulting hierarchical porous structures render the Pt nanoparticles to be more uniformly dispersed in the frameworks as well as the extension of light absorption range,and abundant exposed active species.Most importantly,the formed hetero-structured photocatalysts can promote the effective separation of electro-hole and the enhancement of light response behavior through good synergistic effect.The experimental results showed that the heterojunction photocatalysts of Pt-ZnO-Co₃O₄,Pt-ZnS-CoS,and Pt-Zn₃P₂-CoP have high photocatalytic activity in hydrogen generation.And the efficiency of the hydrogen generation follows an order of Pt-Zn₃P₂-CoP>Pt-ZnS-CoS>Pt-ZnO-Co₃O₄.Especially,the hydrogen generation rate of Pt-Zn₃P₂-CoP reached to 9.15 mmol h^-1g^-1.2.Pd@MOF-derivatives with hierarchical pores as heterogeneous catalysts for Heck coupling reactionsPd@Co₃O₄,Pd@Co₃O₄/C,Pd@Co/CNT catalysts were prepared by fabrication of precursor Pd@ZIF-67 and sunsequent oxidation and carbonization.It was found that the resultant catalysts showed hierarchical porous structures,which not only facilitates the transport of reactants and products in the catalytic reaction,but also renders the noble metal Pd uniformly dispersed in the pores of the derivatives.As a result,the experiments demonstrate that the obtained catalysts display high catalytic activity in the Heck coupling reactions.In addition,the otained catalysts illustrate the high stability with not significantly decreased catalytic efficiency after repeated reactions,accouting for the excellent recyclability.