•  
  •  
 

Corresponding Author

Chong-Tai WANG(wct581@sina.com)

Abstract

Electrochemical properties of the Keggin-type lacunary heteropolysilicate anion SiW11O398- (SiW11) and its indirect electrocatalysis for H2O2 reduction in the supporting electrolyte containing 0.1 mol?L-1 NaHSO4 and Na2SO4 solutions were investigated using cyclic voltammetry, square wave voltammetry and alternating current impedance spectroscopy. Experimental results indicated that SiW11 showed two pairs of reversible redox waves on the glassy carbon (GC) electrode in an acidic solution. The electron transfer number corresponding to the two pairs of waves was one, and the proton transfer number involved was two during the electrode reaction. The diffusion coefficient (D0) of SiW11 calculated from the linear relationship of peak current versus square root of potential scan rate was determined to be 8.92×10-6 cm2?s-1 in 0.1 mol?L-1 NaHSO4 and Na2SO4 solutions. The SiW11 displayed an obvious electrocatalytic activity for the H2O2 reduction. The electrocatalytic peak potential moved to positive direction with the decrease in the solution pH, and the peak current increased. The electrocatalytic process was facilitated by proton through a synergic effect. The pseudo-first order rate constant of the homogeneous reaction was determined to be 0.30 s-1. The indirect electrocatalytic process of SiW11 towards H2O2 reduction was considered to take place through a mechanism involved in a so-call “the seven-coordinate W-O peroxo species”.

Graphical Abstract

Keywords

lacunary heteropolysilicate, electrocatalysis, cyclic voltammetry, alternating current impedance, H2O2 reduction

Publication Date

2012-04-28

Online Available Date

2011-12-16

Revised Date

2011-11-30

Received Date

2011-10-30

References

[1] Rong C Y, Pope M T. Lacunary polyoxometalate anions are .pi.-acceptor ligands. Characterization of some tungstoruthenate(II,III,IV,V) heteropolyanions and their atom-transfer reactivity [J]. Journal of the American Chemical Society, 1992, 114(8): 2932-2938.

[2] Jorgensen K A. Transition-metal-catalyzed epoxidations [J]. Chemical Reviews, 1989, 89(3): 431-458.

[3] Josrgensen K A, Schistt B. Metallaoxetanes as intermediate in oxygen-transfer reactions - reality or fiction? [J]. Chemical Reviews, 1990, 90(8): 1483-1506.

[4] Drago R S. Homogeneous metal-catalyzed oxidations by O2 [J]. Coordination Chemical Reviews, 1992, 117(22): 185-213.

[5] Wang C T, Hua Y J, Li G R, et al. Indirect cathodic electrocatalytic degradation of dimethylphthalate with PW11O39Fe(III)(H2O)4? and H2O2 in neutral aqueous medium [J]. Electrochimica Acta, 2008, 53(16): 5100-5105.

[6] Wang C T, Hua Y J, Tong Y X. A novel Electro-Fenton-Like system using PW11O39Fe(III)(H2O)4? as an electrocatalyst for wastewater treatment [J]. Electrochimica Acta, 2010, 55(22): 6755-6760.

[7] Hua Y J (华英杰), Wang C T (王崇太), Tong Y X (童叶翔), et al. Electrocatalytic degradation of nitrobenzene with Keggin-type PW11O39Fe(III)(H2O)4- [J]. Acta Chimica Sinica (化学学报), 2009, 67(23): 2650-2654.

[8] Wang C T (王崇太), Hua Y J (华英杰), Hua S Y (华淑艳), et al. Photocatalytic degradation of nitrobenzene with Keggin-type Fe(III)-Substituted Heteropolyanion PW11O39Fe(III)(H2O)4- [J]. Acta Chimica Sinica (化学学报), 2010, 68(11): 1037-1042.

[9] Wang C T (王崇太), Hua Y J (华英杰), Li G R (李高仁), et al. Electrocatalytic oxidation of 4-methylpyridine by Cr(III)-substituted phosphorus Heteropolytungstate [J]. Acta Chimica Sinica (化学学报), 2008, 66(8): 835-840.

[10] Server-Carrio J, Bas-Serra J, Gonzalez-Nunez M E, et al. Synthesis, characterization, and catalysis of β3-[(CoIIO4)W11O31(O2)4]10-, the first Keggin-based true heteropoly dioxygen(Peroxo) anion. Spectroscopic (ESR, IR) evidence for the formation of superoxo polytungstates [J]. Journal of the American Chemical Society, 1999, 121(5): 977-984.

[11] Lei P X, Chen C C, Yang J, et al. Degradation of dye pollutants by immobilized polyoxometalate with H2O2 under visible-light irradiation [J]. Environmental Science &Technology, 2005, 39(21): 8466-8474.

[12] Hua Y J (华英杰), Wang C T (王崇太), Li G R (李高仁), et al. Electrochemical properties of the Keggin-type lacunary heteropolytungstate anion and its electrocatalysis for H2O2 reduction [J]. Acta Chimica Sinica (化学学报), 2009, 67(8): 795-800.

[13] Hua Y J (华英杰), Wang C T (王崇太), Wei J C(韦吉崇), et al. Electrocatalytic degradation of nitrobenzene by Keggin-type lacunary heteropolyanion PW11O397- [J]. Acta Chimica Sinica (化学学报), 2010, 68(19): 1961-1964.

[14] Brevard C, Schimpf R, Tourné G, et al. Tungsten-183 NMR: A complete and unequivocal assignment of the tungsten-tungsten connectivities in heteropolytungstates via two-dimensional 183W NMR techniques [J]. Journal of the American Chemical Society, 1983, 105(24): 7059-7063.

[15] Sadakane M, Steckhan E. Investigation of the manganese-substituted α-Keggin-heteropolyanion K6SiW11O39Mn(H2O) by cyclic voltammetry and its application as oxidation catalyst [J]. Journal of the Molecular Catalysis A: Chemistry, 1996, 114(3): 221-228.

[16] Bard A J, Faulkner L R. Electrochemical method, principle and application (电化学方法,原理及应用) [M]. Beijing: Chemical Industry Press, 1986.

[17] Wang C T (王崇太), Hua Y J (华英杰). Concise electro-chemistry principle and application (简明电化学原理及应用) [M]. Haikou: Hainan Press, 2008.

[18] Toth J E, Melton J D, Cabelli D, et al. Electrochemistry and redox chemistry of aquaferrotungstosilicate, H2OFeIIISiW11O395- in the presence of hydrogen peroxide and hydroxyl [M]. Inorganic Chemistry, 1990, 29(10): 1952-1957.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.