Electrostatically Driven Selective Adsorption of Carbon Dioxide over Acetylene in an Ultramicroporous Material

Published

April 19, 2021

Author(s)

Yi Xie, Hui Cui, Hui Wu, Rui-Biao Lin, Wei Zhou, Banglin Chen

Abstract

Separating acetylene from carbon dioxide is highly challenging but important due to their similar physical properties and molecular dimensions. Capturing carbon dioxide from acetylene by virtue of CO₂-selective absorbents can directly produce pure acetylene but rarely realized. Here, we report highly efficient electrostatically-driven CO₂/C₂H₂ 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 towards CO₂ over C₂H₂ with significant sieving effect. This material shows high CO₂/C₂H₂ uptake ratio of (6.0) as well as remarkable CO₂/C₂H₂selectivity of 85 under ambient condition with modest CO₂ adsorption heat (28.8 kJ mol−1), which is superior to other CO₂-selective absorbents. Neutron powder diffraction experiments and molecular simulations reveal 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 C₂H₂ is electrostatically forbidden. Dynamic breakthrough experiments have validated the separation performance of this compound for CO₂/C₂H₂ separation.

Citation

Angewandte Chemie-International Edition

Volume

60

Issue

17

Pub Type

Journals

Keywords

Porous material, gas separation, carbon dioxide, electrostatic potential, nitroprusside

Citation

Xie, Y. , Cui, H. , Wu, H. , Lin, R. , Zhou, W. and Chen, B. (2021), Electrostatically Driven Selective Adsorption of Carbon Dioxide over Acetylene in an Ultramicroporous Material, Angewandte Chemie-International Edition (Accessed January 3, 2025)