Anion Pillared Metal–Organic Framework Embedded with Molecular Rotors for Size-Selective Capture of CO 2 from CH 4 and N 2

The CO 2 sequestration is extremely urgent due to the growing greenhouse effect and the subsequent serious environmental crisis. The development of porous materials with a size-selective effect for CO 2 from other molecules still remains a challenge, due to the difficulties to control pore size within 3–4 Å. Here, we proposed and designed a novel anion-pillared material (termed as ZU-66, ZU = Zhejiang University) embedded with “molecular rotors” toward the industrially relevant CO 2 /CH 4 and CO 2 /N 2 separation. Interestingly, the temporarily fixed molecular rotors under the ambient condition afforded a size-selective channel for CO 2 from CH 4 and N 2 . To our best knowledge, there were only a handful of examples achieving the molecular sieving between CO 2 and CH 4 . Such a behavior endowed ZU-66 with high separation selectivity for both CO 2 /CH 4 (136) and CO 2 /N 2 (355) and high CO 2 capacity (4.56 mmol g –1, 298 K, 1 bar). The actual breakthrough experiment further verified its great potential in both CO 2 /CH 4 and CO 2 /N 2 separation. The specific adsorption behavior within ZU-66 was further revealed through the modeling calculation.