Abstract:

A new green technology of producing chromic anhydride with an electrochemical synthesis method was studied to solve the pollution problems in the traditional production process of chromic anhydride.The anolyte used was sodium dichromate solution, and the anode used was a self-made combination electrode of titanium matrix with a multiple-unit metal oxides active coating.The electrochemical behavior of sodium dichromate solution on a combination electrode of titanium matrix was studied with cyclic voltammetry as a part of the fundamental researches of this technique.The electrooxidation reaction of 160 cycles indicated that the electrode possessed a very stable electrochemical behavior.The peak currents i _p and peak potentials E _p of the oxidation peaks for sodium dichromate solution of different concentrations, i.e ., water under the existence of sodium dichromate, were experimentally measured at different temperatures and sweep rates v on the electrode. The equations of peak current I _p versus v ^1/2 and peak potential E _p versus ln v were established, indicating that the electrode reaction was an irreversible diffusion-controlled reaction. The kinetic parameters and activation energy of electrode reaction was calculated, and the effects of temperature on the kinetic parameters and activation energy were preliminarily discussed.

摘要： 针对铬酸酐传统生产技术中存在问题，开发了电化学合成铬酸酐的绿色新技术. 本技术所用阳极液为重铬酸钠水溶液，阳极为自制钛基多元金属氧化物复合电极. 作为该技术系列基础研究的一部分，本文用循环伏安法研究了重铬酸钠水溶液在钛基复合电极上的电化学性能. 通过160个循环的电氧化反应，表明该电极具有很稳定的电化学性能. 实验测得不同温度、不同扫描速度v、不同浓度重铬酸钠溶液即重铬酸钠存在下水在电极上的氧化峰峰电流ip和峰电位Ep，建立了i_p～v^1/2和E_p～lnv方程,表明电极反应是主要受扩散控制的不可逆反应. 求得电极反应的动力学参数和反应活化能，初步讨论了温度的影响.