球形分枝结构Pt纳米催化剂的合成、纯化及电催化性能  

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

作　　者：司维峰[1,2] 李焕巧[2] 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] 宋玉江[2] 

机构地区：[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

出　　处：《催化学报》2012年第9期1601-1607,共7页

基　　金：国家自然科学基金(21003114;21103163)~~

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36.9nm,其中每一个Pt分枝的直径为2～4nm,长度为4～6nm.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.A new Pt nanocatalyst was synthesized by chemical reduction of K2 PtCl4 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 36.9nm.The branches of the globular dendrites are 24nm in diameter and 4-6nm 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.

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 

分 类 号：O643.36[理学—物理化学]