Synthesis Of PtPdCu Multicomponent Alloy Catalysts For Methanol Oxidation Reaction

Direct Methanol Fuel Cell（DMFC）is a device that can directly convert the chemical energy of methanol fuel into electrical energy.The fuel cell which has the advantages of high working efficiency,fast start-up,environmental friendliness,and portability does not need to be burned and is not limited by the Carnot cycle.The commercial application of DMFC,whose anode is composed of platinum-based materials,is severely restricted due to its high price,complicated preparation process,and being susceptible to poisoning by methanol oxidation intermediates.The performance of the catalyst can be significantly improved by the controllable adjustment of the morphology structure,size and element composition of the catalyst.In this paper,we explored suitable reaction conditions for the characteristics of different components,and successfully prepared ternary ternary PtPdCu nanoparticles and quaternary PtPdCuTe nanowires,then characterized their morphological structure and electrochemical performance.The specific research results obtained are as follows:（1）We successfully prepared PtPdCu nanoparticles at room temperature by wet chemical reduction method.The PtPdCu nanoparticles have higher catalytic activity and stability toward methanol oxidation reaction compared to commercial Pt/C catalysts.The mass activity of PtPdCu is 1247.1 m A · mg_Pt^-1,which is 6.28 times that of commercial Pt/C(198.5 m A · mg_Pt^-1)and the mass activity has only attenuated by 49% after 800 cycles of CV,far below the attenuation of the commercial Pt/C catalyst（62%）after 500 cycles of CV cycle.The remarkable performance can be attributed to the existence of a large number of dislocations and twin boundaries on the surface of the nanoparticles,which exposes more active sites.The introduction of Pd atoms can also promote the dissociation of water and produce Pd-OH_ads which will react with Pt-Co_ads and remove the CO_ads adsorbed on the surface of Pt,so that can release the active site of Pt.And the introduction of Cu not only reduces the content of precious metals,but also can weaken the Pt-CO_ads bond by transferring electrons to Pt,and enhance the catalytic activity of PtPdCu NPs and the ability to resist CO poisoning.（2）We synthesized PtPdCuTe nanowires by using tellurium nanowire sacrificial templates and N,N-dimethylformamide assisted reduction.The Pt₃₈Pd₂₅Cu₇Te₃₀ nanowires with high quality activity and stability were selected by exploring the effect of different Pt and Cu atomic content of PtPdCu Te nanowires toward methanol oxidation reaction.Its mass activity is 7.83 times that of commercial Pt/C.The activity of Pt₃₈Pd₂₅Cu₇Te₃₀ nanowires has only been attenuated by 48%,which is much lower than the 62% mass activity attenuation of commercial Pt/C catalysts after 500 cycles of CV.In addition to the influence of Pd and Cu atoms,its high catalytic activity and stability also benefit from its one-dimensional structure providing more catalytic reaction active sites,and Te atoms during the methanol oxidation reaction,replacing the precious metal etching.