Synthesis Of Pt-based Nanomaterial Catalysts For Electrochemical Properties

Proton exchange membrane fuel cells?PEMFCs?are ideal candidates for transportation and portable power sources due to high efficiencies,reduced emissions,lack of moving parts,and low operating temperatures.It is known that platinum?Pt?is an efficient catalyst for fuel cells as well as various industrial chemical reactions,but its high cost and poor CO resistance impede its large-scale commercialization.One approach to improve the usage of Pt is fabricating Pt-M alloy catalysts by introducing other metals.This paper demonstrates a one-pot approach for producing highly dispersed dendritic palladium-platinum bimetallic nanoparticles with small particle size,tunable composition,and high catalytic activity.Herein,the PdPt bimetallic nanoparticles have been obtained readily via taking advantage of bayberry tannin?BT?as both the reducing agent and surfactant.Additionally,the PdPt bimetallic nanoparticles with different Pd/Pt atomic ratios can be prepared by just varying the amount of Pd and Pt precursors.Most importantly,the as-prepared Pd₅₂Pt₄₈8 catalyst exhibits the optimal catalytic activities compared with other compositional PdPt nanoparticles(Pd₈₂Pt₁₈,Pd₆₉Pt₃₁,Pd₃₆Pt₆₄)and commercial Pt/C?20 wt%?catalyst for the methanol oxidation reaction?MOR?and oxygen reduction reaction?ORR?in acid solution,which can be attributed to the unique dendritic structure and the synergistic effect between Pd and Pt.With evident advantages of the facile preparation and enhanced catalytic performance,it holds great promise as a high-performance catalyst for electrochemical energy conversion.Dendritic nanostructures are attracting the extensive attention in electrocatalysis owing to the open structure and low density.Herein,we report a one-pot route for synthesis of low Pt-content PtPdCu ternary nanodendrites in aqueous solution.The experimental results reveal that PtPdCu trimetallic nanocrystals present enhanced electrocatalytic performance for methanol oxidation reaction and oxygen reduction reaction?ORR?in acid solution compared with commercial Pt/C as well as some state-of-the-art catalysts.In detail,the mass activity of the PtPdCu catalyst with optimized composition is 4.58 A mg_Pt^-1,which is 6 times higher than that of commercial Pt/C catalyst.The good electrocatalytic performance should be attributed to the unique branched nanostructure as well as the synergistic effect among metals.