Reverse Separation of Carbon Dioxide and Acetylene in Two Isostructural Copper Pyridine-Carboxylate Frameworks

Published

July 21, 2024

Author(s)

Jing-Hong Li, You-Wei Gan, Jun-Xian Chen, Rui-Biao Lin, Yisi Yang, Hui Wu, Wei Zhou, Banglin Chen, Xiao-Ming Chen

Abstract

Separating acetylene from carbon dioxide is important but highly challenging due to their similar molecular shapes and physical properties. Adsorptive separation of carbon dioxide from acetylene can directly produce pure acetylene but is hardly realized because of relatively polarizable acetylene binds more strongly. Here, we reverse the CO2 and C2H2 separation by adjusting the pore structures in two isoreticular ultramicroporous metal–organic frameworks (MOFs). Under ambient conditions, copper isonicotinate (Cu(ina)2), with relatively large pore channels shows C2H2-selective adsorption with a C2H2/CO2 selectivity of 3.4, whereas its smaller-pore analogue, copper quinoline-5-carboxylate (Cu(Qc)2) shows an inverse CO2/C2H2 selectivity of 5.6. Cu(Qc)2 shows compact pore space that well matches the optimal orientation of CO2 but is not compatible for C2H2. Neutron powder diffraction experiments confirmed that CO2 molecules adopt preferential orientation along the pore channels during adsorption binding, whereas C2H2 molecules bind in an opposite fashion with distorted configurations due to their opposite quadrupole moments. Dynamic breakthrough experiments have validated the separation performance of Cu(Qc)2 for CO2/C2H2 separation.

Citation

Angewandte Chemie-International Edition

Volume

63

Issue

30

Pub Type

Journals

Download Paper

https://doi.org/10.1002/anie.202400823

Local Download

Citation

Li, J. , Gan, Y. , Chen, J. , Lin, R. , Yang, Y. , Wu, H. , Zhou, W. , Chen, B. and Chen, X. (2024), Reverse Separation of Carbon Dioxide and Acetylene in Two Isostructural Copper Pyridine-Carboxylate Frameworks, Angewandte Chemie-International Edition, [online], https://doi.org/10.1002/anie.202400823, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959153 (Accessed October 14, 2025)