Computer-Aided discovery of MOFs with calixarene-analogous microenvironment for exceptional SF6capture

Abstract

Finding optimal adsorbents to achieve an efficient capture and recovery of sulfur hexafluoride (SF6) from SF6/N2 mixture is of great industrial importance. To address this key challenge, here we present a materials-genomics-accelerated strategy by integrating high-throughput computational screening with subsequent synthesis and adsorption/separation testing of the identified promising material. From over 10140 metal-organic frameworks (MOFs), those with calixarene-analogous pore feature were computationally identified as optimal adsorbents with exceptional SF6/N2 selectivity and SF6 uptake. The separation mechanism was revealed to be thermodynamically driven owing to the synergistic contribution of multiple hydrogen-bond and van der Waals-type SF6/MOF pore wall interactions. As a proof-of-concept, one of the discovered MOFs was further synthesized, and equilibrium adsorption measurements demonstrated both record SF6 adsorption capacity as a single component at 0.1 bar (3.39 mmol g-1) and SF6/N2 IAST-predicted selectivity (~266) under ambient conditions. Besides its excellent regeneration and cycling performance, dynamic breakthrough experiments further confirmed the attractiveness of this MOF for SF6 capture under working conditions.