Preparation And Electrochemical Performance Of Pt-based Nanocatalysts

Due to the ever-increasing energy demand and impending environmental issues in modern society,fuel cells have attracted widespread attention as an renewable energy conversion and storage device.Among them,the direct alcohol fuel cells are widely regarded as promising sources of power for their advantages of high energy density and environmental friendliness.Pt has been the main choice of catalysts for oxidation and reduction reactions in direct alcohol fuel cells.However,the extensive industrial application of direct alcohol fuel cells is severely restricted by the high cost and shortage of Pt.Therefore,it is necessary to understand and study the intrinsic activity of Pt and reduce the use of Pt.In this paper,we incorporated abundant transition metals or non-metals into the precious metal Pt to synthesize composite electrocatalysts with high electrocatalytic activity.The relationship between the surface properties and electrocatalytic performance of the catalyst was explored through experiments.The specific research work is divided into the following three aspects:1.Polyvinylpyrrolidone and oleylamine were used as surfactants to synthesize Co doped Pt nanowires.However,these surfactants binded firmly to the surface of the nanowires,seriously hindering the reactant molecules from entering the active sites.A facile acetic acid/Na BH₄treatment technology is used to remove these surfactants from the surface of the Co-doped Pt nanowires in an effective way.Notably,the morphology of Pt nanowires treated with Na BH₄solution were transformed into nanowire networks with higher crystallinity.The synthesized Co-doped Pt nanowire networks exhibit superior catalytic activities and stability for electrocatalytic oxygen reduction reactions.2.One-dimensional Pt Ni alloy nanowires were synthesized via a facile solvothermal route,and the P was successfully introduced into the Pt Ni structure with Na H₂PO₂·H₂O as the P source under calcination conditions.As revealed by TEM and XRD,the size and crystallinity of the Pt Ni P nanowires changed compared with Pt Ni alloy nanowires.In addition,the EDX analysis further verifies the decreasing content of Ni in Pt Ni P nanowires.Owning to the electronic synergistic effects between one-dimensional nanostructures and different components,the Pt Ni P nanowires exhibit higher electrocatalytic activities towards methanol oxidation reaction compared with Pt Ni alloy nanowires and commercial Pt/C.3.A ternary Pt Ni Co alloy electrocatalyst with one-dimensional structure was synthesized by a facile one-pot method.Owing to the ultrafine sizes and outstanding electron conductivity,the Pt Ni Co nanowires are regarded as an ideal catalyst for ethanol oxidation reaction.Electrochemical measurements demonstrate that the Pt Ni Co nanowires possess superior catalytic activities and excellent durability.