Simultaneous CO₂ capture and metal purification from waste streams using triple-level dynamic combinatorial chemistry

Area of Science:

• Green Chemistry and Sustainable Processes
• Materials Science and Engineering
• Environmental Science and Technology

Background:

• Global warming necessitates significant reductions in carbon dioxide (CO₂) emissions.
• Post-combustion carbon capture technologies are developed but hindered by high costs.
• Direct utilization of captured CO₂ offers an alternative to storage.

Purpose of the Study:

• To explore spontaneous CO₂ fixation by industrial polyamines.
• To develop dynamic libraries of ligands for efficient metal separation and recovery.
• To establish a framework for integrated CO₂ capture and utilization.

Main Methods:

• Utilizing CO₂ fixation with polyamines to create dynamic ligand libraries.
• Optimizing CO₂ loadings and solvent conditions for selective metal precipitation.
• Demonstrating metal separation using vehicle exhaust gas and battery alloy constituents.

Main Results:

• Successful generation of dynamic libraries for metal separation.
• Identification of optimal conditions for CO₂-induced selective metal precipitation.
• Demonstrated separation and recovery of lanthanum and nickel from simulated and real-world sources, including electric vehicle battery alloys.

Conclusions:

• Spontaneous CO₂ fixation by polyamines enables effective metal separation and recovery.
• This CO₂-utilization strategy provides a sustainable framework for integrated capture and use.
• The process shows potential for recycling critical metals from industrial waste streams and alloys.