High-Performance Porous Ionic Liquids for Low-Pressure CO₂ Capture*

Porous ionic liquids are non-volatile, versatile materials that associate porosity and fluidity. New porous ionic liquids, based on the ZIF-8 metal-organic framework and on phosphonium acetate or levulinate salts, were prepared and show an increased capacity to absorb carbon dioxide at low pressures. Porous suspensions based on phosphonium levulinate ionic liquid absorb reversibly 103 % more carbon dioxide per mass than pure ZIF-8 at 1 bar and 303 K. We show how the rational combination of MOFs with ionic liquids can greatly enhance low pressure CO₂ absorption, paving the way towards a new generation of high-performance, readily available liquid materials for effective low pressure carbon capture.