电子活度和pH对二氧化氯制备和稳定性的影响  

Effects of Electron Activity and pH on the Generation and Stability of Chlorine Dioxide

作　　者：裴元生[1] 栾兆坤[1] 陈慧[2] 

机构地区：[1]中国科学院生态环境研究中心环境水化学国家重点实验室,北京100085 [2]西北师范大学化学系,兰州730070

出　　处：《无机化学学报》2001年第3期407-407,共1页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学重点基金资助项目(No.59838300)。

摘　　要：建立了氯体系电子活度（ ρε）和 ｐＨ优势区域图（ ρε－ｐＨ图），从酸化、氧化和还原的角度，探讨了标准状态下 ρε和 ｐＨ对二氧化氯制备和稳定性的影响。实际生产不可能制备绝对纯净的二氧化氯。对于不同的水体，由于其 ｐ ε和 ｐＨ值不同，因而可能使二氧化氨表现出不同的稳定性特征。如果水溶液中二氧化氯不歧化为氯酸根，二氧化氯相对稳定，并与亚氯酸根、氯分子或氯离子稳定共存。当氯体系实现最终平衡时，二氧化氯仅在强酸介质中优势存在，随着酸度降低，二氧化氯歧化为氯酸根和氯气，水溶性二氧化氯在常规ｐＨ条件下不稳定。The predominance area diagrams of electron activity (p epsilon) as a function of pH for chlorine system with multi-oxychlorine species have been constructed. On the base of the diagrams, electron activity and pH directly dominate the generation and stability of chlorine dioxide. Generation processes are in fact to shift the equilibria of chlorine system into the predominance area of chlorine dioxide, which correspond to the processes of acidification, oxidization and/or reduction. It is practically not achievable to generate pure chlorine dioxide from chlorate and chlorite. For different water environments, chlorine dioxide may be present a variation on stability owing to the changed p epsilon and pH values. If no disproportionation of chlorine dioxide into chlorate occurred in aqueous solution, chlorine dioxide would be relatively stable and coexist with chlorite (p epsilon 17.63 and pH > 9.68), molecular chlorine (pH < 0.92), or chloride ion (pH 0.92 similar to 9.68). When chlorine system has already reached the ultimate equilibria, chlorine dioxide is a stable species only in strongly acid media. As the acidity decreases, chlorine dioxide disproportionates into chlorate and molecular chlorine. Aqueous chlorine dioxide is unstable within the normal pH range.

关 键 词：二氧化氯 稳定性 电子活度 三元氯氧化物 平衡模式 PH值 制备 

分 类 号：TQ124.43[化学工程—无机化工]