Liquid Phase Preparation,Structure Characterization And Performance In Fuel Cell Of Pt Based Nanocrystals

Today,with the rapid development of economic,the use of coal and other traditional energy is not only gradually reducing,but also accompanied by many irreversible environmental hazards.Energy has become an urgent problem to be solved.Seeking alternative resources is an effective way to alleviate the current energy crisis.With the advantages of high energy conversion rate and environmental friendliness,fuel cell has become an ideal choice to solve the energy problem.Many studies have found that nano Pt based catalyst has a good catalytic effect on the bipolar reaction of fuel cell.However,the reserves of precious metal Pt are scarce,and its high price limits its large-scale use.Based on the current development of energy and fuel cells,this paper aims to reduce the use of precious metals and reduce costs through hydrothermal synthesis by adding cheap metals,Pt based catalysts with higher activity and better stability were prepared.In this paper,a series of octahedral ptcu nanocrystals with better performance and stability than commercial standards were synthesized by using acetylacetone salt of Pt and Cu as metal ion source,polyvinylpyrrolidone with average molecular weight of 8000 as surfactant,NaI and NaBr as sodium halide salt,halogen ion?Br^-or/and I^-?as composition modifier and DMF as solvent.When I^-and Br^-were added into the reaction at the ratio of 1:2,the area activity of the synthesized Pt₅₉Cu₄₁ nanocrystals in alkaline methanol reached 20.25 mA cm^-2,the mass activity was 3.24 A mg_Pt^-1,4.7times higher than that of commercial palladium black(0.57 A mg_Pd^-1),and 4.3 times higher than that of platinum black(0.61 A mg^-1_Pt).For ethanol oxidation,Pt₅₉Cu₄₁showed the best area activity(34.84 mA cm^-2)and mass activity(5.58 A mg_Pt^-1)in all samples.The PtBiCu nanoalloys was prepared by doping copper in the synthesis of PtBinanocrystals.The structure of the nanocrystals was characterized by XRD and XPS.Through in-situ FTIR analysis,PtBiCu nanoalloys realized the total oxidation of methanol without CO.The mass activity reached 5.25 A mg_Pt^-1 at room temperature,and the durability test for 30 hours showed no current decay.In addition,the mass activity of PtBiCu nanoalloys reached 11.26 A mg_Pt^-1 at 70?.