Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (02): 473-478.doi: 10.3866/PKU.WHXB20110208

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Electrochemical Properties of the Dawson-Type Heteropolytungstate Anion P2W18O626- and Its O2 Reduction Electrocatalysis

WANG Chong-Tai1, HUA Ying-Jie1, SUN Zhen-Fan1, WEI Ji-Chong1, LI Tian-Lue1, TONG Ye-Xiang2, LIU Xiao-Yang3   

  1. 1. School of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, P. R. China;
    2. School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China;
    3. State Key Laboratory of Inorganic Synthesis Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
  • Received:2010-08-02 Revised:2010-10-18 Published:2011-01-25
  • Contact: HUA Ying-Jie E-mail:521000hua282@sina.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20963003), Key Science and Technology Foundation of Hainan Province, China (080305, 090803), Natural Science Foundation of Hainan Province, China (509009), Science and Technology Program Foundation of Jilin Province, China (20090595)

Abstract:

The electrochemical properties of the Dawson-type heteropolyanion P2W18O626- were studied in detail by cyclic voltammetry, alternating current (AC) voltammetry, and AC impedance. Cyclic voltammetry results revealed that P2W18O626- possessed two pairs of reversible one-electron redox waves and two pairs of reversible two-electron redox waves in a solution containing 0.1 mol·L-1 Na2SO4 and NaHSO4 (pH 2.52). The peak potential and the peak current of the single-electron wave were independent of the solution pH while the peak potential of the two-electron wave shifted negatively, and the peak current decreased with an increase in solution pH. This indicated that the two-electron electrode process involved H+ and the involved H+ number was 2. AC impedance spectroscopy showed that the P2W18O626- electrode process was fully controlled by diffusion and the diffusion coefficient (DO) was 2.5×10-6 cm2·s-1. The cyclic voltammograms indicated that significant P2W18O626- electrocatalysis towards O2 reduction to H2O2 occurred as evidenced by the third wave pair and a catalytic efficiency of 300% were obtained. Application of P2W18O626- in the degradation of nitrobenzene in the electro-Fenton-like system containing PW11O39Fe(III)(H2O)4- showed a remarkable improvement in terms of degradation efficiency.

Key words: Dawson-type heteropolytungstate anion, Electrocatalysis, Oxygen reduction, Hydrogen peroxide, Nitrobenzene degradation

MSC2000: 

  • O646.5