Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (09): 2569-2574.doi: 10.3866/PKU.WHXB20100906

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

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).

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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