In silico screening and design strategies of ethane‐selective metal–organic frameworks for ethane/ethylene separation

Abstract

Abstract C 2 H 6 /C 2 H 4 separation is one of the most crucial processes in the chemical industry and currently practiced by energy‐intensive distillation technology. As an alternative, adsorption‐based separation is considered as technically feasible and economically viable, and there has been considerable interest to develop advanced adsorbents for C 2 H 6 /C 2 H 4 separation. In this study, we computationally screen a large set (12020) of metal–organic frameworks (MOFs) to identify top‐performing candidates for selective adsorption of C 2 H 6 over C 2 H 4 . Quantitative relationships are established between the adsorption performance metrics (C 2 H 6 working capacity and C 2 H 6 /C 2 H 4 selectivity) and the structural descriptors (pore size, surface area, and porosity), as well as isosteric heat. We identify 16 top‐performing MOFs with C 2 H 6 /C 2 H 4 selectivity ≥ 2.16 and C 2 H 6 working capacity ≥ 0.54 mol/kg, which are superior to a benchmarked MOF (ZJU‐120a). It is revealed that pore geometry (both size and shape) are the key factors governing C 2 H 6 ‐selective adsorption. From topological analysis, the most common topologies are found. Finally, six design strategies are proposed: regulating topology, catenating framework, adding aromatic ring, pillar‐layering framework, substituting metal node, and imposing flexibility. Each strategy is elaborated with examples for boosting separation performance. These strategies offer bottom‐up guidelines for the rational design of new MOFs towards high‐performance C 2 H 6 /C 2 H 4 separation.