Preparation and CO2 adsorption behavior of ZIF-67-based porous liquids: A molecular dynamics study

Porous liquids (PLs) are fluids with permanent intramolecular pores, which showed high potential in CO2 capture. In this paper, novel Metal-organic Framework (MOF)-based PL has great porosity and abundant adsorption sites, achieving outstanding CO2 adsorption capacity were constructed using ZIF-67 and 18-crown-6 as dispersant. The physicochemical properties and mechanisms were studied by combining molecular dynamics simulations and quantitative calculations. ZIF-67 could be uniformly dispersed in 18-crown-6 through weak interactions, the compound has good fluidity, containing stable CO2 transmission channels and storage pores, endowing it with a high CO2 adsorption capacity than existing porous liquids. The adsorption of CO2 in ZIF-67/18-crown-6 PL is a physical adsorption through van der Waals interaction, and the recycling of the PL can be achieved by adjusting temperature and pressure. It was extra valuable that the fluidity performance of ZIF-67/18-crown-6 PL was confirmed through experimental characterizations. This work not only provides a novel PL system to achieve CO2 capture, but also gives out a new approach for the development of MOF-based functional materials.