Controllable Synthesis And Electrocatalytic Properties Research Of One-dimensional Platinum-based Nanowires

Nanostructures of Platinum（Pt）are of great importance in the area of catalysis due to their distinct physicochemical properties compared to their bulk counterparts.The size and morphology dependent properties of metal nanostructures provide a rational approach for designing highly efficient catalytic materials.In recent years,the nanowires（NWs）and nanorods,based on one dimensional（1D）metallic nanostructures,have been studied with great interests compared with the conventional nanoparticle（NP）catalysts,due to their special structural characteristics such as preferential exposure of reactive crystal facets,high stability,facile electron transport,and high-performance in the applications of the electro catalysts for oxidations and the reduction of oxidants in fuel cell.Therefore,in view of the above reasons,the（researches in）Pt-based nanostructures have important significance and valuable practical applications.Herein,we have explored methods to effectively control the morphology and surface structures of 1D Pt-based NWs,and obtained Pt-Pb NWs,Pt-Cu NWs,Pt-Ni-Pd NWs and Pt-Ni-Pb NWs in this thesis.In addition,the growth mechanisms,structures and structure-activity relationship of the NWs were studied in detail.The main contents are as follows:Chapter 1.The background of the 1D Pt-based NWs,the main points and significance of this subject were introduced in exordium.Chapter 2.A method for preparing hierarchical Pt/Pt_xPb core-shell NWs was proposed.The ultrafine Pt NWs seeds and the sequential introduction of Pt and Pb precursors are key steps for the successful preparation of Pt/Pt_xPb NWs.In addition,the composition of Pt-Pb NWs can be regulated by changing the amount of Pt precursor.The high specific surface area,core-shell structure and the high-index facets making the optimized PtPb_0.27 NWs show outstanding performace in the methanol and ethanol oxidation reaction（MOR and EOR）.Chapter 3.A method for synthesizing screw-like Pt-Cu NWs with high roughness surface was proposed.The composition of Pt-Cu NWs can be changed by different amount of Cu.Ultrafine Pt NWs seeds,subsequent Cu deposition and diffusion are the key to the successful preparation of screw-like Pt-Cu NWs.The Pt-Cu NWs combine the characteristics of 1D structure,alloy effect,Pt-rich surface and high-index facets,exhibiting enhanced activity and stability in MOR and EOR,especially for the PtCu_2.1NWs.Chapter 4.A new method for preparing PtNiPd/PtNi NWs was proposed.Ultrafine PtNi NWs seeds,the different reduction potentials of Pt,Ni,Pd are the most important factor for the preparation of core-shell PtNiPd/PtNi NWs.The internal properties of the 1D structure,the unique core-shell structure,high-index facets and the highly active PtNi shell promote their catalytic performance in ethylene glycol and glycerol oxidation and the oxygen reduction reaction（EGOR,GOR and ORR）.PtNi_0.56Pd_1.42NWs show excellent activity and stability for EGOR,GOR and ORR,indicating the PtNiPd NWs have great potential for the fuel cells reaction.Chapter 5.A method for preparing the ternary PtNi/Pt_xPb/Pt core/multishell NWs was proposed.Ultrafine PtNi NWs,reduction and replacement of Pb,and the preferential reduction of Pt play an important role in the formation of ternary PtNi/Pt_xPb/Pt core/multishell NWs.The compostion of the NWs can be controlled by changing the amount of Pb precursor.Ternary PtNi/Pt_xPb/Pt core/multishell NWs catalysts have ternary,core-shell and 1D structural features,showing enhanced activity and stability for fuel cell reactions.Moreover,the optimized PtNi_0.67Pb_0.26 NWs exhibited excellent activity and stability in the anodic MOR,EOR,EGOR,GOR and the cathodic ORR.