De-Linker-Enabled Exceptional Volumetric Acetylene Storage Capacity and Benchmark C 2 H 2 /C 2 H 4 and C 2 H 2 /CO 2 Separations in Metal-Organic Frameworks.

An ideal adsorbent for separation requires optimizing both storage capacity and selectivity, but maximizing both or achieving a desired balance remain challenging. Herein, a de-linker strategy is proposed to address this issue for metal-organic frameworks (MOFs). Broadly speaking, the de-linker idea targets a class of materials that may be viewed as being intermediate between zeolites and MOFs. Its feasibility is shown here by a series of ultra-microporous MOFs (SNNU-98-M, M=Mn, Co, Ni, Zn). SNNU-98 exhibit high volumetric C 2 H 2 uptake capacity under low and ambient pressures (175.3 cm 3  cm -3 @ 0.1 bar, 222.9 cm 3  cm -3 @ 1 bar, 298 K), as well as extraordinary selectivity (2405.7 for C 2 H 2 /C 2 H 4 , 22.7 for C 2 H 2 /CO 2 ). Remarkably, SNNU-98-Mn can efficiently separate C 2 H 2 from C 2 H 2 /CO 2 and C 2 H 2 /C 2 H 4 mixtures with a benchmark C 2 H 2 /C 2 H 4 (1/99) breakthrough time of 2325 min g -1 , and produce 99.9999 % C 2 H 4 with a productivity up to 64.6 mmol g -1 , surpassing values of reported MOF adsorbents.