Pt/Si_xTi_yO_z/C复合电催化剂的制备及其对氧还原反应的催化作用研究  

PREPARATION OF A COMPOSITE ELECTROCATALYST Pt/Si_xTi_yO_z/C AND ITS CATALYSIS TOWARDS THE REDUCTION OF OXYGEN

作　　者：杨莉君[1] 廖世军[1] 

机构地区：[1]华南理工大学化学与化工学院,广东广州510640

出　　处：《华南师范大学学报（自然科学版）》2009年第A01期48-49,63,共3页Journal of South China Normal University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(20476034;20673040;20876062);广东省科技攻关资助项目(2006A50102003)

摘　　要：首次以正硅酸乙酯和钛酸丁酯处理XC-72R炭黑获得一种复合载体材料,然后采用有机溶胶法制备W(Pt)=20%、W(钛硅氧化物)=4%的Pt/SixTiyOz/C催化剂.XRD图谱显示,该催化剂上负载的Pt纳米颗粒粒径约为1～2 nm.值得关注的是:Pt/SixTiyOz/C虽然与相同Pt载量的Pt/C催化剂具有相似的电化学活性表面积,但是其对于氧还原反应的催化剂活性却比Pt/C大得多.在O2饱和的0.1 mol/L HClO4溶液中,Pt/SixTiyOz/C和Pt/C催化剂ORR极化曲线的扩散电流密度分别为1.6 mA/cm2和2.4 mA/cm2.可见SixTiyOz二元氧化物的添加可以极大地提高催化剂对氧还原反应的催化活性.This article presented the preparation of a novel composite cathode electrocatalyst for ORR.By impregnating XC-72R carbon black with an ethanol solution of tetraethyl orthosilicate and tetrabutyl titanate,a TiSi bioxides doped XC-72R,a composite support material was prepared.Then the composite catalyst Pt/SixTiyOz/C with platinum content of 20% and bioxide content of 4% was prepared by a high pressure colloidal methods.XRD patterns showed that the average particle size of Pt nanoparticles could be as small as ca.1-2 nm.Noticeably,the results of electrochemical testing demonstrated that although Pt/SixTiyOz/C had almost the same electrochemical active surface area（ECSA） with Pt/C.It was much more active for ORR than Pt/C which had the same Pt content.In 0.1 mol/L HClO4 aqueous solution that saturated by O2,the limited diffuse current densities of ORR polarization curves for Pt/SixTiyOz/C and Pt/C were 1.6 mA/cm2 and 2.4 mA/cm2,respectively.A 50% enhancement had been achieved by addition of bioxides.Undoubtedly,the addition of SixTiyOz/C into carbon support can improve the active of the whole electrocatalyst for ORR significantly.

关 键 词：钛硅二元氧化物 阴极催化剂 氧还原反应(ORR) 

分 类 号：TM911.4[电气工程—电力电子与电力传动]