The Synthesis Of Pt-Based Nanostructures And Their Elecatalytic Performance

Noble metal platinum(Pt)as the anode catalyst is widely used in fuel cells,but Pt is expensive and has few reserves in the earth,which is not conducive to the commercial development of fuel cells.Pt-based nanostructures are composed of noble metal Pt and another metal,which not only can increase the utilization of Pt,but also improve the catalytic performance of Pt-based nanomaterials due to the electronic effect and the synergism between the metals.Moreover,the catalytic activity of Pt-based nanomaterials can also be improved by adjusting their size,morphology,composition and structure.Due to the unique size effect,the optical,chemical and physical properties of nanoparticles can be regulated by controlling their size.In comparison with the zero-dimensional(OD),the one-dimensional(ID)nanomaterial has higher structural stability and fast electron transport rate,and which can improve the catalytic performance of fuel cells.Compaired to the 1D nanomaterials,the three-dimensional(3D)nanostructures with larger specific surface area and richer pore structure connectivity can further promote electron transfer and improve catalytic activity and stability.Therefore,it is important to study the size and morphology of Pt-based nanomaterials on the development of fuel cell.In this paper,Pt-based nanomaterials were prepared by a facile one-step synthesis method.The composition and structure of the nanomaterials were analyzed by TEM,XRD etc.characterization methods.The Pt-based nanomaterials were used as electrocatalysts for direct oxidation of alcohols.The main research content of this paper is as follows:(1)The different size of PtAg nanoparticles were prepared by adjusting the amount of phloroglucinol,in which the phloroglucinol plays as reducing agent.Then the different sizes of PtAg nanoparticles of different sizes were used as catalysts in the EGOR and GOR.Electrochemical measurements showed that the smallest PtAg-S catalyst has the best catalytic activity and stability when compared to the three different sizes of PtAg nanoparticles and commercial Pt/C catalysts in EGOR and GOR.(2)One-dimensional Pt-Fe ultrafine nanowires were prepared by one step wet-chemical synthesis.Different components of Pt-Fe ultrafine nanowires were obtained by changeing the amount of Fe precursor.The growth mechanism of Pt-Fe ultrafine nanowires was studied by time tracing experiments.The electrochemical measurements demonstrated that Pt-Fe nanowires had better catalytic activity and stability for the EGOR and GOR in comparison with commercial Pt/C.Therefore,it had a bright application prospect in DEGFCs and DGFCs.(3)Three-dimensional alloy network Pt-Sn nanowires was prepared by one-step solvothermal method.The composition of the network Pt-Sn nanowires was adjusted by changing the amount of Sn precursor.The growth mechanism of network Pt-Sn nanowires was studied by time-tracking experiments.The results of TEM showed that the network Pt-Sn nanowires grew gradually from nanoparticles to network nanowires with the increase of time.All obtained network Pt-Sn nanowires were used as efficient electrocatalysts for EOR and MOR.After 500 cycles of repeated cyclic voltammetry,the network Pt6Sn3 nanowires still exhibited excellent catalytic activity,which confirmed the enhanced stability of the networked Pt6Sn3 NWs.The results illustrated that the network nanowires were promising as a new type of high efficient electrocatalyst.