摘要
考察了搅拌强度、铱的初始浓度、氢分压、盐酸浓度、氯离子浓度、温度及晶种对氢还原铱反应速率的影响.实验表明,氢还原过程是多阶段多步骤联合控制的复杂多相反应,已还原的铱起着自催化作用.同时根据动力学实验结果探讨了反应机理,指出前人未用氢将铱配离子还原为金属乃系其实验温度过低所致.
The effects of stirring, the initial concentration of iridium, partially pressure of hydrogen, concentrations of HC1 and Cl^- temperature and seed crystral on the reduction rate of iridium with hydrogen was studied in the present paper. The experimental results indicated that the procedure of the reduction with hydrogen was a complex multiphases reaction controlled by several stages, the metallic iridium reduced played a part of autocatalyst. The reaction rate during the former stage (including the nucleation) was controlled by chemical reaction, the apparent activation energy was 76.44 kJ/mol at 90～105℃, its apparent first order constant will vary directly proportional to the first power of partial pressure of hydrogen, as well as increase with [HCl] and [Cl^1].However, the reaction rate for the later stage was controlled by the diffusion, the apparent activation energy decreased to 25.62 kJ/mol, and its apparent rate constant was effected greatly by stirring and the initial concentration of iridium, other factors had a slight effects on it. The mechanisms of the reduction was discussed as well. It was pionted that the fact that iridium complex ions can not be reduced to metallic iridium as indicated in previous articles was caused by the lower temperature.
出处
《贵金属》
CAS
CSCD
北大核心
1990年第3期1-12,共12页
Precious Metals
关键词
盐酸
氢还原
铱
动力学
Iridium, Hydrogen reduction, Reaction kinetics, Hydrochloric acid
