物理化学学报 >> 2010, Vol. 26 >> Issue (09): 2569-2574.doi: 10.3866/PKU.WHXB20100906

材料物理化学 上一篇    下一篇

超声辅助法制备双孔空心球状碳化钨及其电催化性能

陈赵扬, 赵峰鸣, 马淳安, 乔芸   

  1. 浙江工业大学化工材料学院,绿色化学合成技术国家重点实验室培育基地,科技部能源材料及应用国际科技合作基地, 杭州310032
  • 收稿日期:2010-01-15 修回日期:2010-05-09 发布日期:2010-09-02
  • 通讯作者: 马淳安 E-mail:science@zjut.edu.cn
  • 基金资助:

    浙江省重大科技专项国际合作项目(2008C14040),浙江省自然科学基金重点项目(Z4100790)和国家自然科学基金(20476097)资助

Ultrasonic-Assisted Preparation of Bimodal Mesoporous HollowGlobal Tungsten Carbide and Its Electrocatalytic Performance

CHEN Zhao-Yang, ZHAO Feng-Ming, MA Chun-An, QIAO Yun   

  1. State Key Laboratory Breeding Base for Green Chemistry Synthesis Technology, International Science&Technology Cooperation Base of Energy Materials and Application, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, P. R. China
  • Received:2010-01-15 Revised:2010-05-09 Published:2010-09-02
  • Contact: MA Chun-An E-mail:science@zjut.edu.cn
  • Supported by:

    The project was supported by the Science and Technology Major Project in International Cooperation of Zhejiang Province, China (2008C14040), Key Project of Natural Science Foundation of Zhejiang Province, China (Z4100790) and National Natural Science Foundation of China (20476097).

摘要:

采用超声空化辅助法制得空心球状结构偏钨酸铵(AMT), 通过固定床气-固反应, 以CO/H2为还原碳化气 氛在700-900oC 下制备得到了介孔结构空心球状碳化钨. 并再次超声处理后分解球型结构得到条状介孔碳化钨. 用扫描电镜(SEM)、X射线衍射(XRD)、热重-差热分析(TG-DTA)、比表面测试(BET)和孔径分布测试(BJH)对样品 进行了表征. 结果表明, 样品组成为单相碳化钨, 且在空气中低于410oC 时具有高稳定性并且具有4和22 nm的双 孔隙分布结构. 将碳化钨粉末制成粉末微电极(PME), 采用循环伏安(CV)技术研究了碳化钨在质子惰性介质中 对硝基苯的电催化还原性能. 结果表明, 相比铂微盘电极, 双孔结构碳化钨对硝基苯还原有着更好的电催化活 性,在峰电位上比铂微盘正移了30 mV, Ip-v1/2关系曲线显示硝基苯在粉末微电极中的还原行为受扩散控制.

关键词: 碳化钨, 超声辅助, 介孔, 电催化

Abstract:

Hollowspherical ammoniummetatungstate (AMT), as a precursor, was prepared by an ultrasonic method. Tungsten carbide (WC) was prepared by a gas-solid reaction in an atmosphere of CO/H2 at 700-900oC. Microspheres were fractured by ultrasonic dispersion for 1 h. X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), Brunauer-Emmett-Teller (BET) surface area, and Barrett- Joyner-Halenda (BJH) pore-size distribution were used to characterize the morphology, mesoporous structure, and thermal stability of the sample. The results indicate that the sample is pure WC. The WC sample is stable in air at 410 oC and the mesopores of WC were centered at 4 nm and 22 nm. A WC powder microelectrode (WC-PME) was prepared using the prepared WC powders. The activity of WC for the electroreduction of nitrobenzene was studied by cyclic voltammetry (CV). The results indicate that the bimodal porosity of WC-PME led to higher catalytic activity than that of a Pt micro disc electrode (Pt-MDE). The reduction potential was 30 mV more positive than that of the Pt-MDE. The relation Ip-v1/2 showed that the electrode reaction was controlled by liquid diffusion.

Key words: Tungsten carbide, Ultrasonic-assistance, Mesoporous, Electrocatalysis