The Synthesis Of Platinum-based Alloy Nanowires And The Study On The Electrocatalytic Properties Of Ethanol

It is very important to promote fuel cell technology to solve the increasingly serious environmental and energy problems.In recent years,the substitution of methanol as a direct fuel of small organic alcohols has been attracted extensive attention,such as ethylene glycol,isopropanol,glycerol,butanol.However,among the many small organic alcohols,ethanol has attracted much attention because of its nontoxic properties,abundant sources,low permeability to methanol,high theoretical energy density,and so on.Therefore,the catalytic oxidation of methanol and ethanol was studied respectively.Pt-based catalyst is a hot topic in fuel cell research,but because Pt is precious metal,it is expensive and has limited reserves.So,it can not only reduce the cost of catalyst when Pt is mixed in to other element to form binary or ternary alloys,but also produce synergistic and electronic effects when different metals form alloys.It can effectively improve the catalytic activity and stability of the catalyst.In this study,PtFe and PtFeNi alloy nanowires with controllable composition were successfully synthesized by one step solvothermal method.The synthesis conditions,catalytic properties and relationship between the composition of nanowires were investigated by means of SEM?XRD and cyclic voltammetry.The following results have been obtained for the electrocatalytic oxidation of ethanol:1.The optimum conditions for the synthesis of nanowires are as follows:KOH 500 mg and the volume ratio of EG/DMF is 4:6,reaction temperature is 180?,as well as the reaction time is 7 h.This reaction system has no surfactant and will not pollute the environment.2.In this system,the morphology and structure of the nanomaterials are similar,and the SEM shows that the nanomaterials which are thin,rough and unsmooth linear structures.3.The average diameter of Pt₁Fe₁ nanowires is about 25 nm,and the average diameter of Pt₁Fe₂ is about 20³0 nm.The average diameter of PtFeNi ternary alloy nanowires is calculated is 21.5 nm,and the diameter of the beam is mainly about 25⁴0 nm,which accords with the normal distribution law,and the average diameter is about 30.1 nm by calculation.4.In this formulation,the synergistic catalytic activity of PtFeNi ternary alloy is stronger than that of PtFe binary alloy nanowires.The maximum mass current density of PtFe alloy nanowires and PtFeNi alloy nanowires for methanol are respectively:0.82 A?mg^-11 and 1.16 A?mg^-1The mass current density of commercial Pt/C is higher than that of commercial Pt/C.5.The maximum mass current density of PtFe alloy nanowires and PtFeNi alloy nanowire catalysts for ethanol electrocatalytic oxidation are respectively:0.35 A?mg^-11 and 0.98 A?mg^-1,it was 1.1 times and 3.06times of commercial Pt/C catalyst,respectively.6.After 3000 cycles of scanning,The mass current density of PtFe and PtFeNi alloy nanowire catalysts decreased by 20%and 28 after cyclic scanning for methanol.For ethanol,the mass current density of PtFe and PtFeNi alloy nanowires decreased by 50%and 28 respectively.Therefore,the stability of PtFe and PtFeNi alloy nanocrystalline catalysts is good.