Preparation Of Pt-based Nanoparticles Catalysts By A Pyrolysis Process Using Multi-walled Carbon Nanotubes As The Reducing Agents And Their Electrochemical Properties

Due to human’s over-exploit and utilize of nature resources, energy shortages andenvironmental pollution problems are becoming increasingly alarming. With a new greaterawareness towards Energy shortage in the future. There is a great emphasis on thedevelopment of more environmental friendly and efficient power supply. Used as electricitygenerated equipment, Fuel cell can directly convert fuel’s chemical energy to electricitypower through electrochemical method, hence it is hopeful to become a clean and highefficient electricity generating equipment, Direct ethanol fuel cells (DEFC s) have attractedmuch attention for their potential application as mobile power source owing to their highenergy density, low toxicity, abundant availability, portable and easy storage. However, thecomplete electro-oxidation of ethanol involves processes such as transferring of12-electron,breaking of C-C bond and enormous adsorbing of intermediates, which set practicalchallenges for the development of effective catalysts. In this case, Developing catalysts withhigh catalytic activity and low cost is urgent for the commercialization of DEFCs.Owing to its specific physical and chemical properties such as excellent electronicconductivity, superior resistance to corrosion and high thermal stability, Carbon nanotubeshave been widely used as catalysts, catalytic supporters, semiconductors, hydrogen storagematerials, super capacitors and so on.Pt and Pt-based particles have extensive applications and are regarded as the most activecatalysts with high selectivity among chemical elements. But the noble metals such asplatinum and palladium have their respective disadvantages such as lacking resource,expensive, difficult to control and short-term utilization. The high price, low storage and easyto be poisoned by CO limit the application of Pt. It is well known that the structure ofnanoparticles has a significantly impact on the catalytic performance. Recently, catalysts withalloy structure have gained great attention just because it not only can improve the utilizationof shell metal, but also greatly enhances the catalytic performance and stability.The main content is as follows:This article mainly describes a simple method about the preparation of a noble metalcatalyst. The catalysts supported on Multi-walled carbon nanotubes (MWCNTs) with Various atomic ratios of Au/MWCNTs and Pt-Pd、Pt-Sn、Pt-Ni、Pt-Au,(denoted as Au/MWCNTs,Pt_xPd_y/MWCNTs, Pt_xSn_y/MWCNTs, Pt_xNi_y/MWCNTs, Pt_xAu_y/MWCNTs) are successfullyprepared by a simple pyrolysis method without an_y addition of reducing agent for the firsttime. In order to prove the most suitable atomic ratio and prepation time of these variouscatalytic, The obtained Au/MWCNTs, Pt_xPd_y/MWCNTs, Pt_xSn_y/MWCNTs, Pt_xNi_y/MWCNTs,Pt_xAu_y/MWCNTs catalysts are characterized by X-ray diffraction (XRD), scanning electronmicroscopy (SEM) and transmission electron microscopy (TEM). The electrocatalytic activityis also examined by CV、EIS and IT in solution basic towards ethanol oxidation reaction(EOR).Main conclusions obtained as follows:1、XRD, EDS, SEM, TEM, and other physical characterization methods prove that in theform of small size Au, Pt-Pd, Pt-Sn, Pt-Ni, Pt-Au particles have been successful modified onthe surface of the multi-walled carbon nanotubes.2、 Cyclic voltammetry, AC impedance and chronoamperometry electrochemicalcharacterization methods have proved that the noble metal catalyst and noble metalalloycatalys (Au/MWCNTs, Pt_xPd_y/MWCNTs, Pt_xSn_y/MWCNTs, Pt_xNi_y/MWCNTs,Pt_xAu_y/MWCNTs) prepared through direct pyrolysis method showed good catalyticperformance to ethanol in alkaline solution.3、A conclusion can be drawn through Exploring the reaction conditions of catalystpreparation process：The most suitable pyrolysis time of Au/MWCNTs catalyst is2h. Themost suitable atomic ratio of Pt_xPd_y/MWCNTs catalyst is Pt: Pd=3:3. The most suitableatomic ratio of Pt_xSn_y/MWCNTs catalyst is Pt：Sn=2.5:1, The most suitable atomic ratio ofPt_xNi_y/MWCNTs catalyst is Pt：Ni=1:1, The most suitable atomic ratio of Pt_xAu_y/MWCNTscatalyst is Pt：Au=1:2.