Chelation of transition metals into MOFs as a promising method for enhancing CO2 capture: A computational study

Metal organic frameworks (MOFs) are one kind of promising porous materials for CO2 capture and separation. In this work, the chelation of the first-row transition metals (from Sc to Zn) into MOFs was proposed to enhance its CO2 adsorption capacity. The adsorption mechanisms and adsorption capacities of CO2 in the chelated MOFs were explored by using quantum mechanical calculation and QM-based grand canonical Monte Carlo simulations. The results show that the chelation of transition metals can significantly improve the adsorption capacity of CO2 in MOFs, especially at low pressure. Among the first row transition metals, the chelation of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) gives higher binding energies than other transition metals. The chelation of Mn(II) into MOFs shows the highest uptake amount at low pressure. The CO2 uptake amounts in UiO(bpydc)-MnCl2 and BPV-MOF-MnCl2 are about six times higher than the original counterparts at 298K and 100kPa. Based on this significant enhancement, the chelation of transition metals in MOFs provides an efficient approach for enhancing CO2 capture.