The Research Of Palladium-based And Hybrid Supports As Catalytic Materials For Fuel Cells

Fuel cells have been widely used nowdays and even play an important role in the future life.People have made a lot of efforts to improve the performances of fuel cells.Papers focus on the electrocatalysts of direct formic acid fuel cells and direct glucose fuel cells,especially the Pd-based catalysts.Different Pd-base alloys and different supports have been prepared to fabricate the effective catalysts.Pd/TiO₂-rGO,PdCr/C catalysts are synthesized for the electrooxidation of formic acid and glucose.The electrocatalysts were characterized by transmission electron microscopy?TEM?,high resolution transmission electron microscopy?HRTEM?,Raman spectroscopy?Raman?,X-ray photoelectron spectroscopy?XPS?and X-ray diffraction?XRD?.Electrochemical performance of the catalysts was investigated by cyclic voltammetry?CV?,linear scanning voltammetry?LSV?and chronoamperometry?CA?.The results were as follows:1.The mixture of graphene oxide?GO?and tetrabutyl titanate?TBT?is used to fabricate the hybrids of TiO₂ and reduced-GO?rGO?by the ethanol solvothermal method.The TiO₂-rGO hybrid and Pd²⁺were co-reduced to fabricate Pd/TiO₂-rGO electrocatalyst.Compared with Pd/rGO electrocatalyst,the as-obtained Pd/TiO₂-rGO started with different TBT:GO ratios?0.47,1.07,1.83,4.26,mass ratios?exhibit higher catalytic activity for formic acid oxidation than Pd/rGO,which indicates that TiO₂-rGO is a promising support for Pd-based electrocatalyst.Among them,the Pd/TiO₂-rGO electrocatalyst started from the precursors with the mass ratio?TBT:GO=1.83?exhibits the highest activity.The peak current density is about 2.1 times as much as that of Pd/rGO.2.The PdCr/C catalysts were prepared by sodium borohydride reduction process.The ethanol electrooxidation performance of Pd Cr/C catalysts in alkaline condition were investigate with electrochemical workstation.Among the PdCr/C catalysts,Pd_0.8Cr_0.2/C catalyst exhibits the highest peak current density and high stability.