Fabrication And Catalytic Performance Of Graphene Oxide Supported Ferrocene Imine Pd/Cu Catalytic Film For Suzuki Coupling Reaction

In this paper,ferrocene imine Pd/Cu bimetallic catalytic film supported on graphene oxide(defined as GO@Fcl-Pd/Cu)by self-assembly and the structure and composition of the catalyst are characterized.The catalytic performance,synergistic effect and catalytic mechanism for Suzuki coupling catalyzed by GO@Fcl-Pd/Cu were systematically studied.The main research contents are as follows:1.Ferroceneimine Schiff base ligand grafted on the surface of GO by self-assembly,then,coordinated with Li2PdCl4/CuCl2 to form an orderly arrangement Pd/Cu bimetallic catalyst(defined as GO@Fcl-Pd/Cu)which was characterized by Fourier transform infrared(FT-IR),X-ray diffraction(XRD),Raman spectroscopy(Raman),X-ray photoelectron diffraction(XPS),Scanning electron microscopy(SEM),scanning electron microscopy-X-ray energy spectrum analysis(SEM-EDX),transmission electron microscopy(TEM)and inductively coupled plasma(ICP-AES).2.The catalytic performance of GO@Fcl-Pd/Cu was studied using Suzuki Miyaura reaction as a template reaction.GO@Fcl-Pd0.1/Cu0.9 prepared with a feed ratio of Pd to Cu is 1:9(measured ratio is 1:1006)had excellent catalytic activity and good stability under the optimized reaction conditions(EtOH/H2O(V/V=1:1),K2CO3,80? for 120 min),and TOF value was as high as 1343740 h-1.It could be recycled for 5 times.The deactivation mechanism of GO@Fcl-Pd0.1/Cu0.9 was investigated by TEM,HR-TEM,Raman and XRD.The results showed that the main reason for the deactivation of the catalyst was the aggregation of metal active centers.The formation of copper oxide and palladium oxide might be considered as another factor.3.The catalytic mechanism was studied by kinetic and thermal filtration experiments,catalyst poisoning experiments,XPS and ReactIR.The results showed that the catalytic reaction occurred at the surface of catalyst;Pd(0)as the active center in Pd/CuO clusters.Through bimetallic synergism,electrons of GO transferred to the metal active center via ligand to Pd,which the metal active center more negative.It made it easy for Pd to react with aryl halide to form oxidation intermediate which might interact with aryl boron acid adsorbed on the adjacent CuO,result in effectively improving the catalytic activity.