A Comprehensive\nComparison Analysis between Ammonium-Based\nand Phosphonium-Based Bifunctional Ionic Liquids for Metal Extraction\nand Separation Processes

A phosphonium-based\nbifunctional ionic liquid (IL) Cyp-IL was synthesized\nto recover molybdenum and vanadium from industrial waste resources,\nsuch as the spent hydrodesulfurization catalysts. In comparison with\nthe reported versatile Aliquat 336-based ionic liquid, the developed\nionic liquid Cyp-IL was investigated for its potential application\nrecovery of vanadium and molybdenum from industrial wastes. To assess\nthe efficiency of the comparative extraction process, a comprehensive\ncomparison analysis was conducted between the ammonium-based bifunctional\nionic liquid Aliquat 336 and the developed phosphonium-based bifunctional\nionic liquid Cyp-IL. Vanadium and molybdenum in the ionic liquid-loaded\nphases were selectively precipitated using NH<sub>4</sub>Cl and BaCl<sub>2</sub> solutions in a basic medium. Compared to Aliquat 336-based\nAli-IL, Cyp-IL exhibited superior performance in the extraction and\nseparation processes of molybdenum and vanadium such as a recovery\nrate of Mo 91% and V 82.5% vs Mo 85% and V 72% by the ammonium-based\nbifunctional ionic liquid Ali-IL. The recovered components, such as\nmolybdenum and vanadium, were characterized by energy-dispersive X-ray\nspectroscopy (EDS), X-ray diffraction (XRD), and scanning electron\nmicroscopy (SEM). This method capacitates the sustainable recovery\nof pure vanadium and molybdenum compounds while minimizing the environmental\nimpact.