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

Abstract

Metal organic frameworks (MOFs) are one kind of promising porous materials for CO 2 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 CO 2 adsorption capacity. The adsorption mechanisms and adsorption capacities of CO 2 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 CO 2 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 CO 2 uptake amounts in UiO(bpydc)-MnCl 2 and BPV-MOF-MnCl 2 are about six times higher than the original counterparts at 298 K and 100 kPa. Based on this significant enhancement, the chelation of transition metals in MOFs provides an efficient approach for enhancing CO 2 capture.

H2physisorption on covalent organic framework linkers and metalated linkers: a strategy to enhance binding strength

“…Previous studies showed that the chelated transition metal with tetrahedral geometry in the COFs has the most favorable binding strength for hydrogen storage to increase the H 2 storage capacity. 11,23,56…”

“…Previous studies showed that the chelated transition metal with tetrahedral geometry in the COFs has the most favorable binding strength for hydrogen storage to increase the H 2 storage capacity. 11,23,56 In the previous section, we have shown that both linker-3-TM-Cl x and linker-5-TM-Cl x have excellent binding enthalpy for more than one H 2 physisorption. Thus, to explore the reason behind the high binding enthalpy, we performed energy decomposition analysis (EDA) and molecular orbital (MO) interaction calculations of both the TM-chelated and the pure linker-3 with the H 2 molecule.…”

“…It would not interact equally compared to Sc, Ti and V chelated linkers with the H 2 molecules. 14,23,56,57 Thus, it would be very interesting to explore the interaction and binding strength of other transition metal chelated linkers and H 2 molecules in the future.…”

Research progress in metal–organic frameworks (MOFs) in CO2capture from post-combustion coal-fired flue gas: characteristics, preparation, modification and applications

“…Using functional ligands that can interact strongly with metals, such as 2,20-bipyridine (bpy), MOFs with accessible chelating sites can be synthesized. 86 Gonzalez et al 87 synthesized metal chelated MOFs by immersing UiO microcrystalline powder in an acetonitrile solution of metal halide salts (CuCl 2 , CuCl, CoCl 2 , and FeBr 2 ) at 80 °C for 5 days. It was found that these metal-chelated MOFs had the same structure as the parent matrix and permanent pores.…”

“…It was found that these metal-chelated MOFs had the same structure as the parent matrix and permanent pores. Hu et al 86 chelated transition metals (from Sc to Zn) into MOFs and used quantum mechanics calculations and QM-based grand canonical Monte Carlo simulations to study the CO 2 adsorption mechanism and capacity. The results showed that the chelation of transition metals could significantly improve the CO 2 adsorption capacity of MOFs under low-pressure conditions.…”