催化学报 ›› 2017, Vol. 38 ›› Issue (10): 1680-1687.DOI: 10.1016/S1872-2067(17)62876-6

• 论文 • 上一篇    下一篇

微波辅助溶剂热法制备Pt/石墨烯-TiO2及其催化性能

王敏, 王中伟, 韦露, 李建伟, 赵新生   

  1. 江苏师范大学物理与电子工程学院, 江苏徐州 221000
  • 收稿日期:2017-03-20 修回日期:2017-06-11 出版日期:2017-10-18 发布日期:2017-10-28
  • 通讯作者: 赵新生
  • 基金资助:

    国家自然科学基金(21376113);江苏省特聘教授项目;江苏省研究生科研创新计划(KYZZ15_0384)。

Catalytic performance and synthesis of a Pt/graphene-TiO2 catalyst using an environmentally friendly microwave-assisted solvothermal method

Min Wang, Zhongwei Wang, Lu Wei, Jianwei Li, Xinsheng Zhao   

  1. School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221000, Jiangsu, China
  • Received:2017-03-20 Revised:2017-06-11 Online:2017-10-18 Published:2017-10-28
  • Contact: 10.1016/S1872-2067(17)62876-6
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21376113), the Jiangsu Specially Appointed Professor Project, and the Graduate Student Scientific Research Innovation Projects in Jiangsu Province (KYZZ15_0384).

摘要:

质子交换膜燃料电池具有比能量高、结构简单、工作温度低、高效清洁和安静无摩擦等优点,是一种非常具有发展前景的电源.燃料电池借用电催化剂把燃料与氧化剂中的化学能转化为电能,通常采用碳粉负载的Pt催化剂.在燃料电池的工作环境下,碳粉载体容易腐蚀和团聚,降低了催化剂活性和稳定性,进而降低了燃料电池的使用寿命.因此,探索高稳定性的催化剂载体有利于提高催化剂的稳定性,促进燃料电池的实用化进程.
为增强催化剂载体的抗腐蚀能力,一些金属氧化物如SnO2,WO3,CeO2和TiO2等被用作催化剂载体.其中,TiO2因具有稳定的化学性能以及与金属之间的“强相互作用”而备受研究者关注.但TiO2载体比表面积小和导电能力弱等缺点限制了它在燃料电池中的应用.石墨烯具有卓越的导电性和比表面积,却容易发生团聚.利用TiO2与碳材料间存在的协同作用,将TiO2与石墨烯复合来制备复合载体,能够增强TiO2的导电能力,抑制石墨烯的团聚,提高催化剂载体的化学稳定性和比表面积.
本文采用微波辅助溶剂热法制备了石墨烯-TiO2复合载体和Pt/石墨烯-TiO2催化剂,研究了TiO2含量对催化剂活性和稳定性的影响.采用X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对制备的样品进行了微观结构和成分表征.结果表明,Pt/石墨烯-TiO2催化剂中TiO2为立方状纳米颗粒,粒径约为60 nm,均匀地分布在石墨烯上;Pt纳米粒子倾向于锚定在TiO2与石墨烯之间,而且分布均匀.采用线性伏安扫描(LSV)和循环伏安法(CV)测试了不同TiO2含量的Pt/石墨烯-TiO2催化剂的活性和稳定性.发现TiO2的加入确实能够提高催化剂的稳定性,随着TiO2含量的提高,催化剂稳定性增加.当TiO2含量为20%时,催化剂的起始电压与极限电流均与Pt/C催化剂接近.经过循环伏安扫描3000圈的快速老化测试后,Pt/石墨烯-TiO2催化剂起始电压的负移明显低于Pt/C催化剂,呈现了优良的稳定性和催化活性.

关键词: 微波辅助溶剂热法, 立方状二氧化钛, 石墨烯-二氧化钛, 氧还原反应

Abstract:

A Pt/graphene-TiO2 catalyst was prepared by a microwave-assisted solvothermal method and was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, and linear sweep voltammetry. The cubic TiO2 particles were approximately 60 nm in size and were distributed on the graphene sheets. The Pt nanoparticles were uniformly distributed between the TiO2 particles and the graphene sheet. The catalyst exhibited a significant improvement in activity and stability towards the oxygen reduction reaction compared with Pt/C, which resulted from the high electronic conductivity of graphene and strong metal-support interactions.

Key words: Microwave-assisted solvothermal method, Cube TiO2, Graphene-TiO2, Oxygen reduction reaction