正丁醛还原Np（Ⅵ）的动力学及机理研究  

THE STUDY OF KINETICS AND MECHANISM OF THE REDUCTION OF NEPTUNIUM(Ⅵ) BY n-BUTYRALDEHYDE

作　　者：吴宇平[1] 林漳基[1] 陈耀中[1] 

机构地区：[1]中国原子能科学研究院

出　　处：《核科学与工程》1996年第3期256-264,共9页Nuclear Science and Engineering

基　　金：核工业科学基金

摘　　要：研究了正丁醛还原ＮＰ（Ⅵ）的动力学，得出其速率方程为：［ＨＮＯ３］［ｎ－Ｃ３Ｈ７ＣＨＯ］。Ｔ＝２０℃，离子强度Ｉ＝１．０时，ｋ＝２．１（ｍｏｌ／ｌ）－２ｍｉｎ－１；测得该反应的活化能Ｅａ＝１２ｋＪ／ｍｏｌ。采用电子自旋共振谱对反应机理进行了研究，初步证明了通过自由基反应的机理。探索了裂片元素钯及３价铁离子对还原反应的可能影响。This thesis studied the kinetics of reduction of neptunium(Ⅵ)by n - butyraldehyde with the following rate equation:-d[NP(Ⅵ) ]/dt = k [Np(Ⅵ)][HNQ3] [ n- C3H7CHO]When T = 20℃and ion strength I = 1. 0, k = 2. 1 (mol/l) -2·min- 1. We got the activation energy Ea = 12kJ/mol and investigated the possible mechanism of the reaction by VO2+ which was the analogy of NP(Ⅵ ). Through observing the E. S. R. spectrum of the spin adducts of the free radicals in the solution with the reaction between VO2 + and n - butyraldehyde, we conclude that two kinds of free radicals exists in the reaction and suggest the possible mechanism of the reaction between n -- butyraldehyde and NPO2' + ion. The determination step of the reaction is the transferingof electrons between the intermediates that are formed from the enol forms of n -- butyraldehydeand NPO2+ ion. So the main factors that affect the reaction rate are: the proPOrtion of enol forms of aldehydes and the degrees of easily transfering of electrons between the intermediates. The POssible effects of some comPOunds containing carbonyl groups on the reduction of Np (Ⅵ ) are discussed. Finally the possible effects of fission element product palladium and iron ion(Ⅲ ) on the reaction are studied and they couldn't result in the increase of percentage of NP(Ⅳ).

关 键 词：正丁醛 镎还原 离子强度 电子自旋共振谱 核燃料后处理 

分 类 号：TL241[核科学技术—核燃料循环与材料]