TY - JOUR
T1 - Halogen–C2H2 Binding in Ultramicroporous Metal–Organic Frameworks (MOFs) for Benchmark C2H2/CO2 Separation Selectivity
AU - Mukherjee, Soumya
AU - He, Yonghe
AU - Franz, Douglas
AU - Wang, Shi Qiang
AU - Xian, Wan Ru
AU - Bezrukov, Andrey A.
AU - Space, Brian
AU - Xu, Zhengtao
AU - He, Jun
AU - Zaworotko, Michael J.
N1 - Publisher Copyright:
© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/4/16
Y1 - 2020/4/16
N2 - Acetylene (C2H2) capture is a step in a number of industrial processes, but it comes with a high-energy footprint. Although physisorbents have the potential to reduce this energy footprint, they are handicapped by generally poor selectivity versus other relevant gases, such as CO2 and C2H4. In the case of CO2, the respective physicochemical properties are so similar that traditional physisorbents, such as zeolites, silica, and activated carbons cannot differentiate well between CO2 and C2H2. Herein, we report that a family of three isostructural, ultramicroporous (<7 Å) diamondoid metal–organic frameworks, [Cu(TMBP)X] (TMBP=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), TCuX (X=Cl, Br, I), offer new benchmark C2H2/CO2 separation selectivity at ambient temperature and pressure. We attribute this performance to a new type of strong binding site for C2H2. Specifically, halogen⋅⋅⋅HC interactions coupled with other noncovalent in a tight binding site is C2H2 specific versus CO2. The binding site is distinct from those found in previous benchmark sorbents, which are based on open metal sites or electrostatic interactions enabled by inorganic fluoro or oxo anions.
AB - Acetylene (C2H2) capture is a step in a number of industrial processes, but it comes with a high-energy footprint. Although physisorbents have the potential to reduce this energy footprint, they are handicapped by generally poor selectivity versus other relevant gases, such as CO2 and C2H4. In the case of CO2, the respective physicochemical properties are so similar that traditional physisorbents, such as zeolites, silica, and activated carbons cannot differentiate well between CO2 and C2H2. Herein, we report that a family of three isostructural, ultramicroporous (<7 Å) diamondoid metal–organic frameworks, [Cu(TMBP)X] (TMBP=3,3′,5,5′-tetramethyl-4,4′-bipyrazole), TCuX (X=Cl, Br, I), offer new benchmark C2H2/CO2 separation selectivity at ambient temperature and pressure. We attribute this performance to a new type of strong binding site for C2H2. Specifically, halogen⋅⋅⋅HC interactions coupled with other noncovalent in a tight binding site is C2H2 specific versus CO2. The binding site is distinct from those found in previous benchmark sorbents, which are based on open metal sites or electrostatic interactions enabled by inorganic fluoro or oxo anions.
KW - acetylene
KW - adsorption
KW - gas separation
KW - halogens
KW - metal–organic frameworks
UR - http://www.scopus.com/inward/record.url?scp=85079598603&partnerID=8YFLogxK
U2 - 10.1002/chem.202000008
DO - 10.1002/chem.202000008
M3 - Article
C2 - 31908047
AN - SCOPUS:85079598603
SN - 0947-6539
VL - 26
SP - 4923
EP - 4929
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 22
ER -