Designed Redox Properties of Strategically Important Metals Through Ionometallurgy

• Applicant: Professor Dr. Gero Frisch
• Subject Area: Metallurgical, Thermal and Thermomechanical Treatment of Materials
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 260201987

Ionometallurgy connects metal speciation with chemical behaviour in ambient temperature ionic fluids and translates these fundamental data into modern metallurgical processes. To date metal processing technology relies commonly on either on energy intensive high temperature techniques (pyrometallurgy) or highly reactive and thus hazardous aqueous solutions (hydrometallurgy). It is the goal of Ionometallurgy to provide technologies that operate at ambient temperatures in a highly efficient and selective manner.To target specific applications in metal processing the properties of metal ions are manipulated by judicious choice of the ligand/solvent. This requires a fundamental understanding of thermodynamic properties such as redox potentials and ligand equilibria as well as electrode surface effects and their origins through speciation. The proposed research will systematically explore the chemical behaviour and thermodynamic properties of strategically important metals, namely elements from group 6, 10, 11 and 13, in ambient temperature ionic solvents. Electrochemical series will be constructed to inform about potential new separation and processing techniques. Spectroscopic and electrochemical methods will be used to produce a toolbox to engineer the metal speciation and reactivity. Classic imidazolium and phosphonium ionic liquids with anions of different ligand strength will be investigated. Deep Eutectic Solvents will uniquely enable us to explore the electrochemical behaviour of cationic compared to anionic complexes in ionic liquid media. These fundamental results will be directed to the development of energy efficient and environmentally responsible alternatives to hydro- and pyrometallurgical methods. Fundamental methodology will be developed to initiate the design of novel metallurgical processes, which do not require toxic or expensive reagents, additives or catalysts, as demonstrated in our preliminary work. Applications such as the economically and ecologically advantageous recycling of valuable metals from electronic waste and electrorefining will benefit from the outcomes of the research.The uniqueness of this work arises from the fact that metal processing in ionic solvents is guided by fundamental research on chemical thermodynamics and in-situ speciation, instead of the emulation of aqueous processes or entirely empirical approaches.

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Participating Persons: Dr. Daniela Freyer; Professor Karl Scott Ryder, Ph.D.; Professor Dr. Wolfgang Voigt