Thermomorphic Multiphase Systems: Switchable Solvent Mixtures for the Recovery of Homogeneous Catalysts in Batch and...

Area of Science:

• Catalysis
• Green Chemistry
• Separation Science

Background:

• Homogeneous transition-metal catalysts are crucial in chemical synthesis but challenging to recover and recycle.
• Thermomorphic multiphase systems (TMS) have emerged as a promising strategy for catalyst recovery over the past two decades.
• TMS facilitate catalyst separation by exploiting temperature-dependent solvent miscibility.

Purpose of the Study:

• To provide a comprehensive review of all studies on thermomorphic multiphase systems for homogeneous catalyst recovery.
• To present the thermodynamic fundamentals governing the temperature-dependent miscibility of solvents in TMS.
• To offer key indicators for comparing different TMS approaches and promote future research.

Main Methods:

• Systematic review of literature on thermomorphic multiphase systems.
• Analysis of thermodynamic principles behind solvent miscibility gaps.
• Compilation and comparison of various TMS applications and solvent systems.

Main Results:

• TMS enable homogeneous reactions at reaction temperature and efficient catalyst recovery via liquid-liquid separation at lower temperatures.
• The use of commercially available solvents makes TMS industrially relevant.
• A framework for comparing different TMS approaches is presented, facilitating further development.

Conclusions:

• Thermomorphic multiphase systems represent a versatile and industrially viable strategy for homogeneous catalyst recovery and recycling.
• Understanding the thermodynamic fundamentals is key to designing and optimizing TMS.
• This review serves as a foundation for developing novel solvent combinations and improving existing TMS technologies.