Abstract
C2H4 and CH4 are essential for industrial applications. However, contamination with other natural gases is a challenge to their utilization. Although several sorbents have been investigated, their performance remains limited. This study introduces graphene-inspired, PPN-20, a porous polymer network (PPN) capable of separating C2H6/C2H4 and purifying CH4 from a C3H8/C2H6/CH4 mixture in a single step. The ultra-microporosity of PPN-20 enables preferential C-H···π interactions with C2H6 and C3H8. As a result, PPN-20 exhibits a C2H6 and C3H8 uptake of 3.93 mmol/g and 5.98 mmol/g, respectively, at 298 K and 1 bar, representing the highest reported for any PPN. It achieves ideal adsorbed solution theory (IAST) selectivities of 2.2 for C2H6/C2H4, 368.2 for C2H6/CH4, 40.14 for C3H8/C2H6, and 294,336 for C3H8/CH4. This selectivity, to the best of our knowledge, is the highest reported for any PPN in the case of C2H6/C2H4 separation and for any sorbent in the cases of C2H6/CH4, C3H8/C2H6, and C3H8/CH4 separation. Robustness tests, including breakthrough experiments, IAST calculations, etc., demonstrate the reliability of PPN-20. Its exceptional performance is attributed to precisely engineered pore sizes that enhance the trapping of guest molecules. These results will pave the way for the design of PPNs for short-chain hydrocarbon purification.
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Acknowledgements
This work was supported by the Robert A. Welch Foundation through an Endowed Chair to H.-C.Zhou (grant no. A-0030). H.W. acknowledges the funding from the National Natural Science Foundation of China (grant no. 22478251). Use of the Texas A&M University Soft Matter Facility (RRID: SCR_022482) and contributions of Dr. Peiran Wei and Dr. Jung Ahn are acknowledged. The authors acknowledge the characterization part of this work performed in the Texas A&M University Materials Characterization Core Facility (RRID: SCR_022202).
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The project was conceived and supervised by K.F., Q.W. and H.-C.Z. K.F. performed the main experiments and characterization of the sorbent. K.F., F.G. and H.W. conducted and analyzed the breakthrough measurement. K.F., H.L. and V.B. did the ss-NMR studies. S.U. and T.T. did the computational studies, and K.F., S.U. and T.T. discussed the results. K.F., S.M. (Sayan Maiti), R.R., L.F. and S.M. (Shengqian Ma) collected and analyzed the gas adsorption data. K.F., S.U., A.M., A.S., U.P., T.T., Q.W. and H.-C.Z. wrote the manuscript.
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Festus, K., Guo, F., Ullah, S. et al. Graphene-inspired porous polymer network for ethane/ethylene separation and methane purification. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70471-7
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DOI: https://doi.org/10.1038/s41467-026-70471-7
