Optimizing Acetylene Sorption through Induced‐fit Transformations in a Chemically Stable Microporous Framework

Developing practical storage technologies for acetylene (C2H2) is important but challenging because C2H2 is useful but explosive. Here, a novel metal–organic framework (MOF) (FJI‐H36) with adaptive channels was prepared. It can effectively capture C2H2 (159.9 cm3 cm−3) at 1 atm and 298 K, possessing a record‐high storage density (561 g L−1) but a very low adsorption enthalpy (28 kJ mol−1) among all the reported MOFs. Structural analyses show that such excellent adsorption performance comes from the synergism of active sites, flexible framework, and matched pores; where the adsorbed‐C2H2 can drive FJI‐H36 to undergo induced‐fit transformations step by step, including deformation/reconstruction of channels, contraction of pores, and transformation of active sites, finally leading to dense packing of C2H2. Moreover, FJI‐H36 has excellent chemical stability and recyclability, and can be prepared on a large scale, enabling it as a practical adsorbent for C2H2. This will provide a useful strategy for developing practical and efficient adsorbents for C2H2 storage. An acid/base‐resistant framework with adaptive pores was prepared; it could effectively capture C2H2 with a record‐high storage density but a very low adsorption enthalpy. Mechanism studies demonstrate that such excellent performance comes from the synergism of active sites, flexible framework, and matched pores, where the adsorbed‐C2H2 can drive framework to undergo continuous induced‐fit transformations, finally leading to dense packing of C2H2.