Precise Pore Space Partitions Combined with High‐Density Hydrogen‐Bonding Acceptors within Metal–Organic Frameworks for Highly Efficient Acetylene Storage and Separation

Abstract The high storage capacity versus high selectivity trade‐off barrier presents a daunting challenge to practical application as an acetylene (C 2 H 2 ) adsorbent. A structure–performance relationship screening for sixty‐two high‐performance metal–organic framework adsorbents reveals that a moderate pore size distribution around 5.0–7.5 Å is critical to fulfill this task. A precise pore space partition approach was involved to partition 1D hexagonal channels of typical MIL‐88 architecture into finite segments with pore sizes varying from 4.5 Å (SNNU‐26) to 6.4 Å (SNNU‐27), 7.1 Å (SNNU‐28), and 8.1 Å (SNNU‐29). Coupled with bare tetrazole N sites (6 or 12 bare N sites within one cage) as high‐density H‐bonding acceptors for C 2 H 2 , the target MOFs offer a good combination of high C 2 H 2 /CO 2 adsorption selectivity and high C 2 H 2 uptake capacity in addition to good stability. The optimized SNNU‐27‐Fe material demonstrates a C 2 H 2 uptake of 182.4 cm 3 g −1 and an extraordinary C 2 H 2 /CO 2 dynamic breakthrough time up to 91 min g −1 under ambient conditions.