Palladium isolation and refining through solvent extraction suffer from limited stability of commercial reagents or limited availability of robust reagents in nitrate media. Several performing extraction solvents based on diamide reagents have been proposed, but their preparation requires synthetic chemistry skills. In the present work, we propose the use of readily accessible N,N,N’,N’-tetrahexylmalonamide (THMA). This reagent revealed superior distribution ratios and selectivity in comparison with previously used diamides for palladium(II) extraction from nitrate media in the frame of palladium recovery from waste. Furthermore, the benefit of excess dihexylamine (DHA) employed during the preparation of THMA was demonstrated through a gain in kinetics performance. Detailed analysis enabled to determine the best performing formulation of extraction solvent, which can be readily prepared from commercially available chemicals without any complex synthesis procedure nor purification step.

通过溶剂萃取分离和精炼钯的问题在于商业试剂的稳定性有限，或者在硝酸盐介质中强效试剂的可用性有限。已经提出了几种基于二酰胺试剂的萃取溶剂，但它们的制备需要合成化学技能。在目前的工作中，我们建议使用易于访问的N,N,N',N'-四己基丙二酰胺（THMA）。在从废物中回收钯的框架中，与以前用于从硝酸盐介质中提取钯 (II) 的二酰胺相比，该试剂显示出优异的分配比和选择性。此外，在 THMA 的制备过程中使用过量的二己胺 (DHA) 的好处通过动力学性能的提高得到了证明。详细分析能够确定性能最佳的萃取溶剂配方，该配方可以很容易地由市售化学品制备，无需任何复杂的合成程序或纯化步骤。