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›› 2007, Vol. 7 ›› Issue (6): 1149-1153.

• 过程与工艺 • 上一篇    下一篇

不同金属氧化物阳极上甲基橙的电化学氧化降解

王树勇,李刚   

  1. 太原科技大学化学与生物工程学院
  • 出版日期:2007-12-20 发布日期:2007-12-20

Degradation of Methyl Orange by Electrochemical Oxidation with Different Oxide Anodes

WANG Shu-yong,LI Gang   

  1. College of Chemical and Biological Engineering, Taiyuan University of Science and Technology
  • Online:2007-12-20 Published:2007-12-20

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摘要： 分别以Ti/SnO2+Sb2O3和Ti/SnO2+Sb2O3/PbO2电极为阳极进行甲基橙的电化学氧化，研究了两种金属氧化物阳极上甲基橙氧化降解过程的反应速率、电流效率及COD的变化.结果表明，两种金属氧化物阳极都能有效氧化降解甲基橙，氧化反应符合一级反应动力学规律，在Ti/SnO2+Sb2O3和Ti/SnO2+Sb2O3/PbO2电极上甲基橙氧化降解过程的表观速率常数分别为0.148和2.43×10-2 min-1. 以Ti/SnO2+Sb2O3为阳极电解30 min，甲基橙的浓度从初始时的0.305 mmol/L降至4.89×10-3 mmol/L，甲基橙的转化率达98.4%；在Ti/SnO2+Sb2O3/PbO2电极上，相同电解时间下甲基橙的浓度只降至0.14 mmol/L，转化率为55.0%. 对不同电极上甲基橙电化学氧化过程电流效率的研究表明，Ti/SnO2+Sb2O3电极的电流效率明显高于Ti/SnO2+Sb2O3/PbO2电极. Ti/SnO2+Sb2O3电极的反应速率大、电流效率高主要源于其较高的析氧电位.

关键词: 氧化物阳极, 电化学氧化, 甲基橙

Abstract: The electrochemical oxidation of methyl orange was carried out using Ti/SnO2+Sb2O3 and Ti/SnO2+Sb2O3/PbO2 electrodes as anodes, respectively. The degradation rate, instantaneous current efficiency (ICE) and chemical oxygen demand (COD) were determined for the different electrodes. It is found that the reaction rate of the electrochemical oxidation of methyl orange on the different anodes follows the first-order reaction kinetics, and the apparent rate constants at 25℃ are 0.147 and 2.43×10-2 min-1 for Ti/SnO2+Sb2O3 and Ti/SnO2+Sb2O3/PbO2 anodes, respectively. When the degradation has lasted for 30 min with the Ti/SnO2+Sb2O3 anode, the concentration of methyl orange decreases from 0.305 mmol/L to 4.89×10-3 mmol/L and the conversion rate of methyl orange is 98.4%, while decreases only to 0.14 mmol/L with the Ti/SnO2+Sb2O3/PbO2 anode at same conditions and the conversion is 55.0%. ICE for the Ti/SnO2+Sb2O3 anode is more than that for the Ti/SnO2+Sb2O3 PbO2 anode. The Ti/SnO2+Sb2O3 anode with a higher oxygen evolution potential presents high reaction rate and current efficiency for the elimination of methyl orange.

Key words: oxide anode, electrochemical oxidation, methyl orange