One‐Step Ethylene Purification from Ternary Mixtures in a Metal–Organic Framework with Customized Pore Chemistry and Shape
Qi Ding, Zhaoqiang Zhang, Yulong Liu, Kungang Chai, Rajamani Krishna, Sui Zhang
Abstract
Abstract Adsorptive separation is an energy‐efficient technology for the separation of C2 hydrocarbons. However, it remains a critical problem to directly produce high‐purity C 2 H 4 from ternary C 2 H 2 /C 2 H 4 /C 2 H 6 mixtures by simultaneously trapping C 2 H 2 and C 2 H 6 . Herein, we report the one‐step C 2 H 4 purification from the ternary mixture by a metal–organic framework Zn(ad)(int) (ad=adeninate; int=isonicotinate). The material combines dense heterocyclic rings and accessible uncoordinated O atoms as strong binding sites for C 2 H 6 and C 2 H 2 . Its spindle‐like cage exhibits an interesting shape matching with the targeted molecules, affording Zn(ad)(int) not only high separation selectivity for C 2 H 6 /C 2 H 4 and C 2 H 2 /C 2 H 4 , but also excellent gas capacity. Breakthrough experiments show that polymer‐grade C 2 H 4 can be separated from the ternary mixtures with a record productivity of 1.43 mmol g −1 . In situ powder X‐ray diffraction and Fourier transform infrared spectrum analyses further provide deep insights into the separation mechanism.