An Ultrastable Supramolecular Framework Based on Consecutive Side‐by‐Side Hydrogen Bonds for One‐Step C2H4 / C2H6 Separation

One‐step efficient separation of high‐purity C2H4 from C2H4 / C2H6 mixtures by HOFs faces two problems: lack of strategies for constructing stable pores in HOFs and how to obtain high C2H6 selectivity. Herein, we have developed a microporous Mortise‐Tenon‐type HOF (MTHOF‐1, MT is short for Mortise‐Tenon structure) with a new self‐assembly mode for C2H4 / C2H6 separation. Unlike previous HOFs which usually possess discrete head‐to‐head hydrogen bonds, MTHOF‐1 is assembled by a unique consecutive side‐by‐side hydrogen bonds, which result in mortise‐and‐tenon pores decorated with orderly arranged amide groups and benzene rings. As expected, MTHOF‐1 exhibits excellent stability under various conditions and shows obvious separation trends for C2H6 / C2H4. The IAST selectivity is as high as 2.15 at 298 K. More importantly, dynamic breakthrough experiments have demonstrated that MTHOF‐1 can effectively separate the C2H6 / C2H4 feed gas to obtain polymer‐grade C2H4 in one step even under high‐humidity conditions.