铜氨水系中一价铜氨络离子的氧化

Oxidation of ammoniacal cuprous complex ion in copper ammonia water system

微细铜粉是可替代贵金属生产电子浆料的重要原材料。在常压铵盐歧化工艺生产微细铜粉过程中， 制取一价铜氨络离子溶液是关键步骤， 而一价铜氨络离子在空气中极易被氧化。借助Ｃｕ（ Ⅱ）／Ｃｕ（ Ⅰ） 电对氧化还原电位的测定来获知不同时刻一价铜氨络离子的浓度， 研究了一价铜氨络离子的氧化速度及其影响因素。实验表明：溶液温度越低、气相中氧分压愈小、ＮＨ３·Ｈ２Ｏ 浓度越大以及ＮＨ＋４ 的加入均有利于阻缓一价铜氨络离子的氧化。

Fine copper powder has potentiality to be used instead of precious metals powder for preparation of conductive ink. In production of fine copper powder by disproportionation of ammoniacal cuprous salt under normal pressure, the preparation of cuprous complex solution is the key to the whole process owing to its high oxidability in the air. The oxidation rate of Cu(Ⅰ) and factors influencing on it were investigated by electrochemical method, i.e. measuring the redox potentials of Cu(Ⅱ)/Cu(Ⅰ) couple as a function of [Cu(Ⅰ)] at different moments and conditions. Experimental results showed that decreasing the p (O 2) or the reaction temperature and increasing the concentration of NH 3·H 2O or NH + 4 are all helpful to inhibit the oxidation process.