ABSTRACT Ultra‐microporous molecular sieving materials offer exceptional size‐ and shape‐selective gas separation, yet their practical use is often limited by slow diffusion kinetics and low adsorption capacities. Here, we report a low‐cost manganese‐based metal‐organic framework (MOF), Mn‐dcbp, featuring an adaptive “corner‐pocket” channel structure. While retaining C 2 H 2 /C 2 H 4 sieving selectivity, the material successfully integrates a high acetylene (C 2 H 2 ) uptake (126.3 cm 3 /cm 3 ) with ultrafast diffusion kinetics (k = 0.01863 s −1 ). In situ single‐crystal x‐ray diffraction reveals a sub‐angstrom‐level structural adaptation mechanism induced by C 2 H 2 , leading to ordered, high‐density packing of C 2 H 2 within the channels and achieving a record storage density of 1.02 g/mL. Strong host–guest interactions enable the material to maintain excellent C 2 H 2 adsorption capacity (110.6 cm 3 /cm 3 ) even at elevated temperatures (75 °C), while also demonstrating superior separation performance for C 2 H 2 /C 2 H 4 and C 2 H 2 /CO 2 gas mixtures. Furthermore, Mn‐dcbp can be produced on a large scale via an environmentally friendly route and exhibits excellent, water, thermal, and cycling stability, which is crucial for potential industrial implementation.
Han et al. (Wed,) studied this question.