First-principles-guided design of ionic liquids for CO2 capture

The identification of sorbents that combine selectively and reversibly with CO2 is essential for efficient and economical abatement of ever-increasing CO2 emissions. Room temperature ionic liquids (ILs) are a promising class of potential absorbents, especially when modified to chemically combine with CO2. In this perspective we describe the evolution of IL-based CO2 capture chemistries over the last ten years and in particular the important role that first principles simulations have played in helping guide those developments. Current anion-functionalized ILs achieve high CO2 capture efficiencies tailorable to a wide range of separation conditions and avoid the viscosity problems that plagued the earliest amine-functionalized, CO2-reactive ILs. Further progress is needed to develop ILs able to meet all the requirements of a CO2 separation system, and simulations will play a central role in those developments.