Study on the Preparation and Performances of Thermoresponsive Imprinted Polymers for Selective Separation and Purification of Ru(III)

Ruthenium, one of the platinum group elements, plays a crucial role in industrial development, and it is important to develop a material to separate and purify ruthenium with high efficiency to ensure its supply. Herein, a thermoresponsive Ru(III)-imprinted polymer (Ru(III)-TIIP) was prepared by combining thermoresponsive technology, Pickering emulsion technology, and imprinted technology. The Ru(III)-TIIP could regulate its structure by controlling the external temperature and maintained good adsorption and separation performance. The structure and performances of Ru(III)-TIIP were tested and evaluated by Fourier transform infrared, scanning electron microscopy, energy-dispersive spectrometry, transmission electron microscopy, specific surface area, porosity analysis, zeta potential, X-ray photoelectron spectroscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectrometry. The results showed that the maximum adsorption capacity (Q) of Ru(III)-TIIP was 0.2203 mmol/g under 33 °C. The maximum desorption rate (D %) was 78.1%, which was reached at 25 °C. When Fe(III) was used as the interfering ion, the separation degree (R) of Ru(III)-TIIP was 3.2. Meanwhile, the study of the adsorption process of Ru(III)-TIIP to Ru(III) was more suitable to be expressed by pseudo-first-order kinetics and the Langmuir model. When Ru(III)-TIIP was applied to the platinum group catalyst leach solution, the content of platinum group elements ranged from 53.72 to 82.09% after one adsorption/desorption cycle. In addition, Ru(III)-TIIP had maintained 66.14 and 81.25% of the original capacity for Q and R after 11 adsorption/desorption cycles.