PbO_2阳极在硫酸铬电解氧化制备重铬酸时的电极行为

Behavior of PbO_ 2 Anode in the Preparation of Dichromic Acid by Electrooxidation of Chromium Sulfate

采用XRD和SEM对 2种电极的活性组分进行了表征 ,并测定了比表面积 ,发现PbO2 /Ti电极比PbO2 /Pb电极含有较多的 β PbO2 和较大的比表面积。用稳态极化曲线法测定了 2种电极在H2 SO4介质中Cr2 (SO4) 3 电氧化的电化学参数。考察了硫酸介质中PbO2 /Pb和PbO2 /Ti2种电极作为阳极电解氧化硫酸铬制备重铬酸的平均电流效率和操作稳定性 ,80 0h实验结果表明 ,PbO2 /Ti阳极有较好的电催化活性和电化学稳定性 ,优于PbO2 /Pb电极。

The active phases of electrodes were characterized by XRD, SEM and surface area measurement. It was found that the active phase of PbO 2 /Ti electrode contains more β PbO 2 and possesses larger specific surface area than that of PbO 2 /Pb electrode. The electrochemical parameters in the oxidation process of Cr 2 (SO 4 ) 3 were determined by steady state polarization curve. The current efficiency of PbO 2 /Pb and PbO 2 /Ti electrodes in the preparation of dichromic acid by electrooxidation chromium sulfate and stability of the electrodes were investigated. The results showed that the PbO 2 /Ti electrode exhibited better electrocatalytic activity and electrochemical stability than PbO 2 /Pb electrode in the course of 800 h test.