Electrostatically Driven Selective Adsorption of Carbon Dioxide over Acetylene in an Ultramicroporous Material. (10th March 2021)

• Record Type: Journal Article
• Authors: Xie, Yi; Cui, Hui; Wu, Hui; Lin, Rui‐Biao; Zhou, Wei; Chen, Banglin
• Is Part Of: Angewandte Chemie. Volume 133:Number 17(2021)
• Page Start: 9690
• Page End: 9695
• Publication Date: 2021-03-10
• Subjects: cadmium nitroprusside -- carbon dioxide -- electrostatic potential -- gas separation -- ultramicroporous materials; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202100584
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Separating acetylene from carbon dioxide is important but highly challenging owing to their similar physical properties and molecular dimensions. Herein, we report highly efficient electrostatically driven CO2 /C2 H2 separation in an ultramicroporous cadmium nitroprusside (Cd‐NP ) with compact pore space and complementary electrostatic potential well fitting for CO2, thus enabling molecular quadrupole moment recognition of CO2 over C2 H2 . This material shows a high CO2 /C2 H2 uptake ratio of 6.0 as well as remarkable CO2 /C2 H2 selectivity of 85 under ambient conditions with modest CO2 heat of adsorption. Neutron powder diffraction experiments and molecular simulations revealed that the electrostatic potential compatibility between pore structure and CO2 allows it to be trapped in a head‐on orientation towards the Cd center, whereas the diffusion of C2 H2 is electrostatically forbidden. Dynamic breakthrough experiments have validated the separation performance of this compound for CO2 /C2 H2 separation. Abstract : As enabled by the compact pore space and the complementary electrostatic potential fitting for CO2 molecules, ultramicroporous cadmium nitroprusside showed molecular quadrupole moment recognition towards CO2 over C2 H2 (see picture) with a high CO2 /C2 H2 uptake ratio of 6.0 and CO2 /C2 H2 selectivity of 85. Dynamic breakthrough experiments validated the potential of this compound for CO2 /C2 H2 separation.