Department of Chemistry Seminar - Lan Huang, PhD Candidate, University of Saskatchewan
Lan Huang, PhD candidate in the Department of Chemistry, University of Saskatchewan, will present a seminar at 1:30 pm via Zoom.
Title
Ligand Development of Coordination and Selective Extraction of Platinum Group Metals
Abstract
Platinum group metals (PGMs) are widely used in many chemical processes, especially as automotive catalysts. Palladium, platinum and rhodium are extensively employed in automobile catalytic converters for converting exhaust emissions into nonpolluting gases. Until February of 2021, global auto catalyst demand of PGMs was over 13 million oz, which is the second-highest global total ever recorded. To meet the future market demand, it is necessary to recover PGMs from secondary resources. Solvent extraction is one of the most effective techniques for recovery of platinum, palladium and rhodium from their mixed metal aqueous media in hydrometallurgical methods.
The Foley group has previously found that dithiobiuret-based ligands are highly effective and selective extraction of gold over base metals. With this inspiration, the extraction of PGMs with dithiobiuret-based ligands has been investigated. In this talk, I will describe the one-pot synthesis of dithiobiuret-based ligands. Their oxygen analogues: monothiobiuret and biuret are also successfully synthesized. These ligands have been investigated into the coordination chemistry of palladium, platinum and rhodium and the dithiobiuret-based ligands exhibit a high affinity for palladium, which indicates that dithiobiuret-based ligands show a good potential to be a selective extractant for palladium in a solvent extraction system. Then, I will discuss the extraction behavior of dithiobiuret-based ligands in the solvent extraction experiment. The extractability (E%) of palladium can reach 99% and the solvent extraction conditions have been optimized. With the least solvent used and fast time of extraction in mild acidic media, dithiobiuret-based ligand is potential to be the best extractant for palladium extraction ever reported. I will demonstrate that dithiobiuret-based ligands possess a remarkably high efficiency (99%) for extraction of palladium from solutions containing a mixture of metal ions even the molar ratio between Pd and ligand is only 1 to 1.
Date: Friday, December 10
Time: 1:30 pm
Zoom link available by request to chem.dept@usask.ca