Role of Molecular Modeling in the Development of CO₂-Reactive Ionic Liquids

Ionic liquids (ILs) have gained considerable attention in recent years as CO₂-reactive solvents that could be used to improve the economic efficiency of industrial-scale CO₂ separations. Researchers have demonstrated that IL physical and chemical properties can be optimized for a given application through chemical functionalization of both cations and anions. The tunability of ILs presents both a great potential and a significant challenge due to the complex chemistries and the many ways in which ILs can be made to react with CO₂. However, computer simulations have demonstrated great potential in understanding the behavior of ILs from the underlying molecular interactions. In the present review, we examine how computer simulations have aided in the design of ILs that chemically bind CO₂. We present the historical development of CO₂-reactive ILs while highlighting the insights provided by molecular modeling which aided in understanding IL behavior to further experimental findings. We also provide a brief discussion of simulations focused on ionic liquids that physically dissolve CO₂. We conclude with a discussion of areas where simulations can yet be used to advance the current understanding of these complex systems and an outlook on the use of computer simulations in the design of optimal ILs for CO₂ separations.