High-Performance Adsorbent for Ethane/Ethylene Separation Selected through the Computational Screening of Aluminum-Based Metal-Organic Frameworks.

The development of a high-performance ethane (C 2 H 6 )-selective adsorbent for the separation of ethane/ethylene (C 2 H 6 /C 2 H 4 ) gas mixtures has been investigated for high-efficiency adsorption-based gas separation. Herein, we investigated Al-based metal-organic frameworks (MOFs) to identify an efficient C 2 H 6 -selective adsorbent (CAU-11), supported by a computational simulation study. CAU-11 exhibited numerous advantageous properties (such as low material cost, structural robustness, high reaction yield, and high C 2 H 6 /C 2 H 4 selectivity) compared to other Al-based MOFs, indicating immense potential as a C 2 H 6 -selective adsorbent. CAU-11 exhibited preferential C 2 H 6 adsorption in single-component gas adsorption experiments, and its predicted ideal adsorption solution theory selectivity of C 2 H 6 /C 2 H 4 was over 2.1, consistent with the simulation analysis. Dynamic breakthrough experiments using representative compositions of the C 2 H 6 /C 2 H 4 gas mixture confirmed the excellent separation ability of CAU-11; it produced high-purity C 2 H 4 (>99.95%) with productivity values of 0.79 and 2.02 mol L -1 while repeating the cyclic experiment with 1:1 and 1:15 v/v C 2 H 6 /C 2 H 4 gas mixtures, respectively, at 298 K and 1 bar. The high C 2 H 6 /C 2 H 4 separation ability of CAU-11 could be attributed to its non-polar pore environment and optimum pore dimensions which strengthen the interaction of its pores (via C-H···π interactions) with C 2 H 6 to a greater extent than with C 2 H 4 .