The Study Of The Electro-Oxidation Behavior Of Propanol On Pt Hollow Nanospheres Modified Glassy Carbon (GC) Electrode

Due to its merit of high energy conversion efficiency and less pollution, the research of fuel cell is of great value to electro catalysis. And the Direct Alcohol Fuel Cell (DAFC) has attractive prospect of development because of its safety, cheap and no needing of the reforming of hydrogen.Nowadays the expensive metal Platinum is thought of the most effected catalyst in fuel cell of DAFC. But it is also known as its fatal disadvantage that it can adsorb CO very strongly, resulting in the toxin of catalyst,and its nanoparticles and other nano-materials are easy to agglomeration to inactivate because of high surface area and high surface energy . So it is still a challenging subject to develop new making method that can enhance the catalytic efficiency and stability of Platinum,reduce the cost by lowering its usage,enhance the toxin resistance of Platinum based catalyst. Some related researches have been carried out such as adding the second metal (Ru, Sn, Mo etc.) or metal oxide (WO3) or dual-metal catalyst or tri-metal catalyst. Recently years, with the constant new research, nan-metal hollow material (hollow sphere, hollow tube etc.)has its promising prospect applied in optics,electrology,magnetology and catalysis[0] for its distinct physical and chemical property(stable structure,good catalyst activity,long used life etc.). Therefore, the controllable synthesis of various sizes and shape of the nano-tube,construct nano-sphere and other nano-materials have been attracted wide attention.Being a kind of small alcohol molecule, propanols are also ideal fuel in DAFC. But the present research focused on methanol, ethanol, and relatively fewer propanols. Therefore, it is the task of this paper study to synthesis Pt nano-sphere,construct Pt nano-sphere modified electrode and research the electro catalytic-oxidization behavior of n-propanol and iso-propanol on Pt hollow nanosphere modified GC electrodes (H-Pt/GC), mainly in the following aspects:(1)Adopt template method to synthesis Pt nanoparticle with controllable size and adjustable shell thickness, and characterize the surface topography,composition and structure of Pt hollow nanosphere (H-Pt) catalyst by using SEM,EDS and cyclic voltammeter (CV), to study the synthesis mechanism and optimize the preparation process of H-Pt;(2)Explore the electro-catalytic oxidization behavior of n-propanol and iso-propanol in acidic solution respectively, and find that n-propanol disintegrating adsorption of CO can poison the electrode ,only after CO is oxidized in high potential can the electrode activity get recovered; However, there are H adsorption and desorption peak during the electro-catalytic oxidization of iso-propanol, which means that Pt electrode is not poisoned. It is proved that there are different electro-oxidation mechanisms between n-propanol and iso-propanol on H-Pt/GC electrode under the acid conditions. The former is processed by dual path reaction mechanism characterized with active intermediates and toxicity of intermediate; the latter by successive oxidation reaction mechanism.(3)Respectively research the electro-catalytic oxidization behavior influence of n-propanol and iso-propanol on H-Pt/GC electrode with reactants concentration,scanning speed and supporting electrolyte, and Here are some findings: (â… )Under the concentration range in this experiment, H-Pt/GC electrode can be used electric analysis sensor for n-propanol and iso-propanol;(â…¡)the electro-catalytic oxidization of n-propanol and iso-propanol are controlled by diffusion steps;(â…¢)With the increase of supporting electrolyte pH , the electrode -catalytic activity gradually increasing on H-Pt/GC electrode for n-propanol, specifically in alkaline solution, but in neutral solution for iso-propanol with the same condition;(4)After compared study of the electro-oxidation behavior of Propanol on H-Pt/GC,B-Pt/GC and N-Pt/GC electrodes in different mediums ,we find :(â… )Regardless of the type of medium, H-Pt/GC electrode has the best electro-catalytic oxidization activity for n-propanol and iso-propanol;(â…¡)After a long time CV scanning, H-Pt/GC electrode is the most stable in acid or neural solutions; But N-Pt/GC electrode is the most stable in alkaline solution.