Selective adsorption of SF6 in covalent- and metal–organic frameworks

Sulfur hexafluoride (SF6) is an extremely severe greenhouse gas. It is an urgently important mission to find excellent candidates for selective adsorption of SF6, in order to reduce the emission of SF6 facilities. Here, we adopt the molecular simulation method to systematically explore the selective adsorption of SF6 in 22 kinds of representative covalent-and metal–organic frameworks. Results indicate that COF-6 is a promising candidate for the SF6 adsorption at low pressure P < 20 kPa because of its small pore size, while MOF-180 and PAF-302 are excellent candidates at high pressure P = 2 × 103 kPa due to their large Brunauer-Emmett-Teller specific surface area (BET-SSA) and pore volumes. For the two cases of the power industry (XSF6=0.1) and the semiconductor industry (XSF6=0.002) environments, COF-6 and ZIF-8 are fairly promising candidates for selective adsorption of SF6 from the SF6/N2 mixtures, because they not only present the high selectivity, but also the large adsorption capacity at ambient environment, which can be considered as potential adsorbents for selective adsorption of SF6 at ambient conditions.