Au-Pd/石墨烯和Au-Pd/碳纳米管催化电化学氧化甲酸
高 丽，吕逍雨, 杨海堂, 杨敬贺*,毛立群
【摘 要】摘 要：利用化学还原法合成了石墨烯和碳纳米管负载的Au-Pd纳米粒子. 石墨烯负载的Au-Pd纳米粒子(Au-Pd/G)的粒径远小于碳纳米管负载的Au-Pd纳米粒子(Au-Pd/CNTs)的粒径, 且Au-Pd纳米粒子在复合材料上分布均匀. 与碳纳米管负载的Au-Pd纳米粒子催化剂相比, 石墨烯负载的Au-Pd催化剂对甲酸的催化显示出更好的电催化活性, 结果表明作为Au-Pd纳米粒子的基底,石墨烯可以明显提高Au-Pd纳米粒子的电催化活性. 在0.1 mol/L H2SO4中, 该纳米修饰电极对甲酸有良好的电催化作用, 甲酸在电极上的氧化动力学过程为扩散控制过程. 【期刊名称】化学研究 【年(卷),期】2015(000)006 【总页数】5
【关键词】金-钯纳米粒子;碳纳米管;石墨烯;甲酸氧化 【
文
献
来
源
】
https://www.zhangqiaokeyan.com/academic-journal-cn_chemical-
research_thesis/0201235499573.html
Received date：2015-08-11.
Foundation item：Supported by the National Natural Science Foundation of China (21403053) and the Joint Funds of the National Natural Science Foundation of China (U1404503).
Biography：GAO Li(1982-), female, majoring in industrial crystallization and
electrochemical
research.
*Corresponding
author,
E-mail:
jhyang@henu.edu.cn.
As a kind of promising power source, direct formic acid fuel cell (DFAFC) offers a wide potential application. In recent years, Pd has been shown to be a good catalyst for the low temperature electro-oxidation of formic acid[1]. However, Pd catalyst loses easily a large amount of its activity owing to the oxidation of Pd surfaces and the poisoning adsorption of COads species[2]. In order to improve the activity and stability of Pd catalyst, various Pd-based catalysts have been developed successfully[3-5]. Among various doping elements, Au is the very attractive element for Pd-based binary catalysts probably because Au can promotes electron transfer for Pd and accordingly enhances the catalytic activity[6]. Pd-Au bimetallic catalysts instead of monometallic Pd can enhance the electrochemical activity for fuel molecules oxidation[7]. As a new branch of carbon materials, carbon nanotubes (CNTs) and graphene (G) have been found numerous applications in catalytic field[8-9].
In this work, graphene supported Au-Pd nanoparticles (Au-Pd/G) and carbon nanotubes supported Au-Pd nanoparticles (Au-Pd/CNTs) were synthesized by a chemical reduction method. The Au-Pd/G catalyst shows a higher electrocatalytic activity for the formic acid electrooxidation compared to the Au-Pd/CNTs catalyst indicating the substrate graphene can obviously enhance the catalytic activity of Au-
Pd nanoparticles.
1 Experimental
1.1 Reagents
Nafion (5% ethanol solution, mass fraction) was purchased from Alfa Aesar, and diluted to 0.1% with doubly distilled water in use. H2SO4 (98%) was purchased from Zhongping Engergy and Chemicals Group Kaifeng Dongda Chemical Co.,Ltd (Henan, China). (NH4)2PdCl4 and (NH4)AuCl4·H2O(54.98%) were purchased from Alfa Aesar.
1.2 Synthesis of Materials
The Au-Pd/G catalyst with 20% Pd and 5% Au were prepared as follows. Firstly, 100 mg graphene, 2.9 mL NH4AuCl4·H2O (4.18 g·L-1), 12.5 mL (NH4)2PdCl4 (5.709 g·L-1) and 8 mL THF were thoroughly mixed together. Then the ultrasonic dispersion suspension (1 h) was stirred for another 12 h in a flask. After that, 35 mL mixture solution of 0.1 mol/L NaBH4 and 0.1 mol/L Na2CO3 (pH=10) were added into the system which was kept stirring for one more hour at room temperature. Finally, the above mixture was filtered and sequentially washed with triply distilled water and ethanol. The precipitate was collected and dried in a vacuum oven at 333 K. For comparison, the Au-Pd/CNTs catalyst was prepared by the same method. And the control Pd/G and Pd/CNTs catalyst with 20% Pd or the Au/G and Au/CNTs catalyst with 5% Au was fabricated similarly except that only corresponding Pd or Au salt
Au-Pd／石墨烯和 Au-Pd／碳纳米管催化电化学氧化甲酸
