Novel polyazamacrocyclic receptor impregnated macroporous polymeric resins for highly efficient capture of palladium from nitric acid media

[Display omitted] •Synthesis of a novel polymeric resin with a specific binding ability to Pd(II).•Rapid kinetics, high adsorption capacity and selectivity toward Pd(II) in HNO3 and HCl media.•A new column separation system for practical enrichment and recovery of Pd(II).•New insights into the binding mechanism of polyazamacrocyclic receptors to Pd(II). A novel composite resin C8-Cyclen/CG-71M, with the specific binding ability to palladium ions in HNO3 solution, was developed by impregnating tetraoctyl-substituted 1,4,7,10-tetraazacyclododecane (C8-Cyclen) receptor into the macroporous polymeric resins (Amberchrom CG-71M). The structure and morphology of obtained products were fully characterized. Study on the batch experiments revealed that C8-Cyclen/CG-71M resin exhibited rapid kinetics, favorable adsorption ability and high selectivity toward Pd(II) in a wide HNO3 concentration. The theoretical interpretation of the experimental data by employing kinetics models, Langmuir/Freundlich isotherms and thermodynamic equations were implemented to describe the adsorption behavior. The results showed that the adsorption process of Pd(II) by C8-Cyclen/CG-71M was comforted to a monolayer-coverage with the maximum adsorption capacity of 169.5 mg/g. Besides, the XPS analysis was performed to probe the underlying adsorption mechanism to Pd(II). A suggested mechanism involving the synergistic effect of four cyclic amines in C8-Cyclen receptors was proposed to describe the interaction manner between Pd(II) and C8-Cyclen/CG-71M. Furthermore, the resin was also applied to recovery Pd(II) from HCl media and similar results were obtained. Overall, due to the benign synthesis, efficient adsorption ability and facile operation, C8-Cyclen/CG-71M might be a promising resin material for Pd(II) selective capture from radioactive wastes, and other leaching solution of spent catalysts and electronic scraps.