催化学报

催化学报 ›› 2012, Vol. 33 ›› Issue (9): 1601-1607.DOI: 10.3724/SP.J.1088.2012.20431

• 研究论文 • 上一篇    

球形分枝结构 Pt 纳米催化剂的合成、纯化及电催化性能

司维峰1,2, 李焕巧2,a, 尹杰2, 李书双2, 谢妍2, 李佳2, 吕洋1,2, 刘元2, 邢永恒1, 徐缓1,b, 宋玉江2,c   

  1. 1辽宁师范大学化学化工学院, 辽宁大连 116029; 2中国科学院大连化学物理研究所洁净能源国家实验室, 催化基础国家重点实验室, 辽宁大连 116023
  • 收稿日期:2012-04-16 修回日期:2012-07-03 出版日期:2012-09-11 发布日期:2012-09-11

Synthesis, Purification, and Electrocatalytic Activity of Platinum Nanocatalyst with Globular Dendritic Structure

SI Weifeng1,2, LI Huanqiao2,a, YIN Jie2, LI Shushuang2, XIE Yan2, LI Jia2, LÜ Yang1,2, LIU Yuan2, XING Yongheng1, XU Huan1,b, SONG Yujiang2,c   

  1. 1College of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029, Liaoning, China; 2Dalian National Laboratory for Clean Energy, State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
  • Received:2012-04-16 Revised:2012-07-03 Online:2012-09-11 Published:2012-09-11

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摘要： 以非离子型表面活性剂 Brij-35 为稳定剂, 以水为溶剂, 在常温、常压条件下利用抗坏血酸还原 K2PtCl4 制备了 Pt 纳米催化剂, 采用透射电子显微镜、能量弥散 X 射线谱、X 射线粉末衍射、热重及循环伏安扫描对催化剂进行了表征. 结果表明, 所制 Pt 纳米催化剂为尺寸均一的球形分枝结构, 平均粒径为 36.9 nm, 其中每一个 Pt 分枝的直径为 2~4 nm, 长度为 4~6 nm. 为去除表面活性剂 Brij-35 和副产物, 开发了一种简单的多次水洗法以纯化所制 Pt 纳米催化剂. 表征结果证明, 该法可有效去除表面活性剂和副产物, 所得催化剂纯度与商业 Pt 黑 (99.9%) 相当, 且电化学活性比表面积更高, 在氧还原反应和甲醇氧化反应中表现出更高的电催化活性.

关键词: 球形分枝结构, 电催化活性, 表面活性剂, 铂纳米催化剂, 氧还原, 甲醇氧化

Abstract: A new Pt nanocatalyst was synthesized by chemical reduction of K2PtCl4 by ascorbic acid in the presence of a non-ionic surfactant Brij-35 (CH3(CH2)10CH2(OCH2CH2)23OH) in aqueous solution at room temperature. The obtained Pt nanocatalyst was characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction, thermogravimetry (TG), and cyclic voltammetry (CV). The uniform Pt nanocatalyst possesses a globular dendritic morphology with a mean diameter of 36.9 nm. The branches of the globular dendrites are 2-4 nm in diameter and 4–6 nm in length. A simple purification method with multiple water washing was developed to remove Brij-35 and other by-products from the surface of Pt nanocatalyst. TG, EDX, and CV results show that the surface of Pt nanocatalyst after purification is as clean as that of commercial Pt black (fuel cell grade, 99.9%). Compared with commercial Pt black, Pt nanocatalyst demonstrates a higher electrochemical active surface area and significantly improved electrocatalytic activity to oxygen reduction and methanol oxidation.

Key words: globular dendritic structure, electrocatalytic activity, surfactant, platinum nanocatalyst, oxygen reduction, methanol oxidation