The Size Of Pallidium Nanoparticles Was Controlled By Sulfhyl Functionalized Graphenen Oxide And The Properties Of The Catalyst

In recent years,graphene and its derivatives have received great attention due to their unique optical,mechanical and electrical properties.Graphene was oxidized,on the carbon surface was modified hydroxyl,carboxyl and carbonyl oxygen containing groups,and its intrinsic properties have been greatly changed due to the presence of these oxygen-containning groups,which has the advantages such as band width adjustable,high dispersion and high reactive activity.Moreover,the rich oxygen-containing functional groups of graphene oxide provide the possibility for the functionalization of its surface.In this paper,by using 3?thioyl triethoxy silane?MPTES?covalent modification of graphene oxide obtained thiol functionlization of graphene oxide.With it we obtained different sizes of palladium nanoparticles,and we applied those catalysts to Heck and Benzoic Acid Hydrogention,the ultrsmall Pd nanoparticles exhibited good catalytic activity,this paper is divided into three parts:The first part,due to the difference in the number of oxygen-containing functional groups obtained from different methods,the appropriate load the MPTS on the graphene oxide was discussed.With different amount of MPTS,the obtained materials were characterized.The second part,we used the GO?SH?n as the carrier,and followed anchoring the palladium ion on to it,we got the Pd²⁺/GO?SH?n,and then we can restore it in the atmosphere of hydrogen.These series of catalysts were used in the Heck coupling reaction,it was found that the amount of sulfhydryl was different in the same amount of palladium,and the catalytic activity was very different.Through the characterization of the catalyst,it was that the amount of sulfhydryl group had a great influence on the particle size of palladium.We concluded that the size of palladium nanoparticles could be controlled by controlling the amount of sulhydryl.At the same time,we obtained Pd nanoparticles with high dispersion and particle size is 1.43 nm.Through the control of the carrier we had improved the utilization of precious matals.The third part,in order to expand application of Pd/GO?SH?5,We applied it to the selective hydrogenation of benzoic of acid,which has high industrial application value,to produce cyclohexane carboxylic acid reaction,and hydrogenation of benzoic acid derivatives.At 120?and2.5 MPa pressure,hydrogen benzoic acid conversion rate can reach 99.6%,the selectivity of cyclohexane carboxylic acid reached 99%,and compared with other supported Pd catalysts,such as Pd/AC,Pd/CNT,Pd/TiO₂,Pd/CeO₂,Pd/MgO,Pd/??Al₂O₃ in the same condition of benzoic acid conversion rate.The catalytic is not as good as that of Pd/GO?SH?5,indicating that the high dispersion and ultra-small size of palladium obtained also have good industrial application value.