化学学报 ›› 2005, Vol. 63 ›› Issue (22): 2027-2031. 上一篇    下一篇

研究论文

直接甲醇燃料电池阳极催化剂的新体系: 纳米TiO2-CNT-PtNi复合纳米催化剂

褚道葆*,1,冯德香1,张金花1,林华水2,胡维玲2,田昭武2   

  1. (1安徽师范大学化学与材料科学学院 安徽省功能性分子固体重点实验室 芜湖 241000)
    (2厦门大学化学系 固体表面物理化学国家重点实验室 厦门 361005)
  • 投稿日期:2005-01-17 修回日期:2005-07-28 发布日期:2010-12-10
  • 通讯作者: 褚道葆

Novel System of Direct Methanol Fuel Cell Anode Catalysts: NanoTiO2-CNT-PtNi Complex Catalysts

CHU Dao-Bao*,1, FENG De-Xiang1, ZHANG Jin-Hua1, LIN Hua-Shui2, HU Wei-Ling2, TIAN Zhao-Wu2   

  1. (1 Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Materials Science,
    Anhui Normal University, Wuhu 241000)
    (2 State Key Laboratory for Physical Chemistry of the Solid Surface, Department of Chemistry,
    Xiamen University, Xiamen 361005)
  • Received:2005-01-17 Revised:2005-07-28 Published:2010-12-10
  • Contact: CHU Dao-Bao

采用电合成前驱体Ti(OEt)4直接水解法和电化学扫描电沉积法制备纳米TiO2-CNT-PtNi复合纳米催化剂. 透射电镜(TEM)和X射线衍射(XRD)测试结果表明, 纳米PtNi合金粒子(平均粒径8 nm)均匀地分散在纳米TiO2-CNT复合膜的三维网络结构中. 通过暂态电化学方法研究表明, 复合纳米催化剂的电化学活性比表面积为90 m2/g, 对甲醇氧化具有很高的电催化活性和稳定性, 常温常压下甲醇氧化峰电位为0.67和0.44 V, 当温度为60 ℃时, 氧化峰电位负移至0.64和0.30 V, 氧化峰电流密度高达1.38 A/cm2. 复合纳米催化剂对甲醇电氧化的高催化活性和稳定性可归因于多元复合纳米组分的协同催化作用, 这种作用导致CO在复合纳米催化剂上的弱吸附, 从而避免了催化剂的中毒.

关键词: 直接甲醇燃料电池, 阳极催化剂, 纳米TiO2, 碳纳米管, 纳米PtNi合金粒子, 复合纳米催化剂, 甲醇电氧化, 扫描电沉积

The nanoTiO2-CNT-PtNi complex catalysts were prepared by the direct hydrolysis of electrosynthetic precursor Ti(OEt)4 and electrochemical scan electrodepositing method. The results of XRD and SEM show that the PtNi nanoparticle of average size 8 nm was dispersed uniformly on nanoTiO2-CNT complex film surface. The electrocatalytic activity of the nanoTiO2-CNT-PtNi complex catalysts was investigated by cyclic voltammetry and chronopotentiogram. The results indicated that the nanoTiO2-CNT-PtNi complex catalysts with Pt loading of 0.32 mg/cm2 exhibited high electrochemically active surface area of 90 m2/g and very high electrocatalytic activity and stability for electro-oxidation of methanol. The oxidation peak potential of methanol was 0.67 and 0.44 V at room temperature in atmosphere pressure, respectively, and shifted to 0.64 and 0.30 V at 60 ℃ and the oxidation peak current of methanol was 1.38 A/cm2. The high electrocatalytic activity and good stability can be attributed to the synergistic catalytic effect of nanocomposite, which leads to the weak adsorption of CO on complex nanostructure catalysts, avoiding poisoning of the catalysts.

Key words: direct methanol fuel cell, anode catalyst, nanocrystalline TiO2, carbon nanometer tube, PtNi alloy particle, complex catalyst, electro-oxidation of methanol, scan electrodepositing