Speciation of Ruthenium(III) Chloro Complexes in Hydrochloric Acid Solutions and Their Extraction Characteristics with an Amide-Containing Amine Compound
Speciation of Ruthenium(III) Chloro Complexes in Hydrochloric Acid Solutions and Their Extraction Characteristics with an Amide-Containing Amine Compound
复制标题
盐酸溶液中钌(III)氯配合物的形态及其用含酰胺胺化合物的萃取特性
作者：
Tomoya Suzuki;Takeshi Ogata;Mikiya Tanaka;Tohru Kobayashi;H. Shiwaku;T. Yaita;H. Narita
铂族金属的精炼主要基于溶剂萃取法，而Ru则通过蒸馏以RuO4的形式选择性地回收。用萃取代替蒸馏有望简化提纯过程。为了建立一种有效的Ru萃取体系，我们用紫外可见光谱和Ru K边扩展X射线吸收精细结构分析了Ru在盐酸中的形态，并考察了N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide)胺和三辛胺对Ru的萃取性能。EXAFS和UV-Vis光谱表明，随着盐酸浓度的增加，在0.5-10M的盐酸溶液中，Ru的主要形态由[RuCl4(H2O)2]−转变为[RuCl6]3−。Ru在EHBAA体系中的萃取率(E%)随HCl浓度的增加而增加，在[HCl]=5M时达到80%，较高的HCl浓度时，萃取率下降；TOA的萃取率较低。萃合物的EXAFS分析表明，Ru~(3+)在其内部配位球面上有5Cl-−和1H2O。[RuCl5(H2O)]2−在[RuCln(H2O)6−n]3−n上的分布与EHBAA体系中E%对HCl浓度的依赖关系相似，表明EHBAA体系中的五氯物种被EHBAA抽提.
The refining of platinum group metals is based mainly on solvent extraction methods, whereas Ru is selectively recovered by distillation as RuO4. Replacement of distillation by extraction is expected to simplify the purification process. To develop an effective extraction system for Ru, we analyzed the Ru species in HCl with ultraviolet-visible (UV-Vis) and Ru K-edge extended X-ray absorption fine structure (EXAFS) spectroscopies, and we examined the properties of Ru extracted with N-2-ethylhexyl-bis(N-di-2-ethylhexyl-ethylamide) amine (EHBAA) and trioctylamine (TOA). EXAFS and UV-Vis spectra of Ru in HCl solutions revealed that the predominant Ru species in 0.5–10 M HCl solutions changed from [RuCl4(H2O)2]− to [RuCl6]3− with the HCl concentration. The extraction percentages (E%) of Ru in the EHBAA system increased with increasing HCl concentration, reached 80% at [HCl] = 5 M, and decreased at higher HCl concentrations; the corresponding E% for TOA were low. EXAFS analysis of the extracted complex indicated that the Ru3+ had 5 Cl− and 1 H2O in its inner coordination sphere. The similarity of the dependence on HCl concentrations of the E% in the EHBAA system and the distribution profile of [RuCl5(H2O)]2− on [RuCln(H2O)6−n]3−n suggested that the EHBAA extracted the pentachlorido species.
影响因子：
2.5
作者：
Ravel, B;Newville, M
通讯作者：
Newville, M