Study On MOFs Encapsulating Nano-alloy (Au,Ag,Pt) And Its Catalytic Properties

As an inorganic-organic hybrid porous material,metal-organic frameworks(MOFs),have been widely used in catalysis,hydrogen storage,adsorption,separation and photoelectric materials and other fields,due to their high specific surface area,uniform adjustable pore size and structure diversities and other advantages.As a good carrier matrix,MOFs can form novel composite materials with metal nanoparticles(MNPs)of different compositions and structures.In this paper,ZIF-8 and DUT-52 were used as carriers to encapsulate MNPs,synthesizing various core-shell catalysts MNPs@MOFs,and their catalytic activities were studied.1.Composite materials M@ZIF-8(M=Au,Au@Ag,Au@PtAg)were assembled with Au NRs,Au@Ag NRs and Au@PtAg NRTs with unique nanotattle structure as the cores and ZIF-8 as the shell;the assembly process of M@ZIF-8 and the effect of PVP on the encapsulation process were studied.And a series of characterizations of these composites had been made.2.The catalytic activities of ZIF-8,Au@ZIF-8,Au@Ag@ZIF-8 and Au@PtAg@ZIF-8 in CO2 photocatalytic reduction and the reverse water gas shift reaction(RWGS)were investigated.The catalytic results indicated that Au@PtAg@ZIF-8 had better catalytic activity and selectivity,which was due to the unique gap of NRTs providing more active sites for the catalytic reaction and the synergistic effect between different metals.The catalysts remained stable after photocatalysis,indicating that ZIF-8 could be used as a good photocatalytic carrier.3.The morphology of DUT-52 was regulated by adjusting the amount of acetic acid and solvent ratio(DMF/CH3CH2OH)to determine the optimal synthesis conditions and a series of characterizations of DUT-52 were carried out.Using DUT-52 as the carrier,the mono-dispersive core-shell composite materials M@DUT-52(M=Pt/Ag@Au NRTs)was synthesized by coating spherical bell nanoparticles with unique structure(Pt/Ag@Au NRTs).The morphologies of M@DUT-52 were regulated by adjusting the amount of polyvinyl pyrrolidone(PVP)and acetic acid.In this paper,the design,preparation and catalytic effect of the composite materials provide a new research direction for MOFs and its composite materials in catalytic applications.