De‐Linker‐Enabled Exceptional Volumetric Acetylene Storage Capacity and Benchmark C₂H₂/C₂H₄and C₂H₂/CO₂Separations in Metal–Organic Frameworks

Abstract

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 C2H2 uptake capacity under low and ambient pressures (175.3 cm3 cm−3 @ 0.1 bar, 222.9 cm3 cm−3 @ 1 bar, 298 K), as well as extraordinary selectivity (2405.7 for C2H2/C2H4, 22.7 for C2H2/CO2). Remarkably, SNNU‐98‐Mn can efficiently separate C2H2 from C2H2/CO2 and C2H2/C2H4 mixtures with a benchmark C2H2/C2H4 (1/99) breakthrough time of 2325 min g−1, and produce 99.9999 % C2H4 with a productivity up to 64.6 mmol g−1, surpassing values of reported MOF adsorbents.

Water-Resistant, Scalable, and Inexpensive Chiral Metal–Organic Framework Featuring Global Negative Electrostatic Potentials for Efficient Acetylene Separation

“…In the past 5–10 years, significant progresses have been made in the field of employing MOFs as sorbents for efficient C 2 H 2 /C 2 H 4 and C 2 H 2 /CO 2 separation, resulting in remarkable C 2 H 2 capture capacity and selectivity by leveraging crystal engineering principles. − The dominating principles are the introduction of coordinatively unsaturated metal sites (CUMSs), also known as open metal sites (OMSs), into microporous MOFs for reinforcing framework–C 2 H 2 interactions through typical side-on coordination between the CC bonds and OMSs. For example, Long et al reported the Fe-MOF-74 featuring high density exposed square pyramidal Fe 2+ sites capable of binding C 2 H 2 with strong affinity .…”

Highly Selective Separation of C2H2/CO2 and C2H2/C2H4 in an N-Rich Cage-Based Microporous Metal-Organic Framework

“…In recent decades, MOFs [6][7][8][9][10][11][12] have been studied widely in separations and purifications for hydrocarbons [13][14][15][16][17][18][19][20][21][22][23][24]. However, the molecular sizes (3:3 × 3:3 × 5:7 Å 3 for C 2 H 2 , 3:2 × 3:3 × 5:4 Å 3 for CO 2.2.…”

Porous materials with suitable pore size and dual‐functional sites for benchmark one‐step ethylene purification

“…The significant advance in porous materials [5][6][7][8][9][10][11][12][13][14][15][16][17] in the last decade has aroused interests of researchers to seek adsorptive separations to make the challenging separation processes more energy-efficient. The developed ordered-assembly porous materials, like metal-organic frameworks (MOFs), [18][19][20][21][22][23][24] covalent organic frameworks (COFs), 25,26 etc, provide an excellent platform for tailor-made porous materials that are adaptive for different guest molecules and have obtained considerable achievements in C 2 H 4 purification. Porous materials decorated with ordered anions, 3 and polar functional groups, 27 like -OH, open metal sites, 28 have realized highly efficient capture of trace C 2 H 2 from C 2 H 4 .…”