Porous aromatic frameworks with metallized catecholate ligands for CO2 capture from gas mixtures: A molecular simulation study

Abstract

Carbon dioxide (CO2) capture from industrial gas mixtures, including flue gas, natural gas, and syngas is very important. Physical adsorption based on porous framework materials is quite promising for CO2 capture. In this work, we systematically investigated the separation performance of CO2 from CO2/N2, CO2/CH4, and CO2/H2 gas mixtures in porous framework materials with metallized catecholate ligands. The results indicated that the metallized catecholate ligands, including alkaline earth metals (Be, Mg, and Ca) and first-row transition metals (Sc to Zn), exhibit significantly effect on CO2 capture in porous framework materials. Specially, the selectivity of CO2 over N2, CH4, and H2 in the PAF-303 containing metallized catecholate ligands at initial pressure can reach up to 939.02 (PAF-303-Zn), 1775.5 (PAF-303-Cr), and 36555.24 (PAF-303-Cr), respectively. Furthermore, the incorporation of several transition metals can result in the revised N2 adsorption over CO2 owing to the strong selective back bonding with the N2 but not the CO2. The above results indicated that the materials containing metallized catecholate ligands are promising candidates for CO2 capture form flue gas, natural gas, and syngas.