CO2 Chemical Trap and Electronegative Microenvironment Enable Metal–Organic Framework with One‐Step Ethylene Purification from Quaternary Mixture

Abstract One‐step purification of C 2 H 4 from a four‐component CO 2 /C 2 H 6 /C 2 H 2 /C 2 H 4 mixture with a single adsorbent is of great significance but very challenging. Herein a feasible and general strategy is reported for constructing chemical traps in MOF featuring an electronegative microenvironment in the pore wall for one‐step purification of C 2 H 4 from the four‐component mixture. The enzyme‐mimicking Zn‐OH sites in CFA‐Zn‐OH, acting as a CO 2 chemical trap, can efficiently fix CO 2 while the electronegative pore wall in MOF ensures the preferential adsorption of C 2 H 2 and C 2 H 6 impurities, thus leading to the one‐step purification of C 2 H 4 from a four‐component mixture. Mechanism studies reveal that the Zn‐OH sites in CFA‐Zn‐OH can chemically fix CO 2 impurity in a reversible manner to form bicarbonate Zn‐HCO 3 , mimicking the carbonic anhydrase. In addition, the negative electrostatic potential of the pore wall allows CFA‐Zn‐OH to preferentially capture C 2 H 2 , and C 2 H 6 impurities, thus ensuring one‐step C 2 H 4 purification from the four‐component mixture. Column breakthrough experiments validated its ability for one‐step C 2 H 4 purification on from the four‐component mixture and C 2 H 4 with a purity of 99.9% can be directly harvested.