Nanowire-like C<sub>2</sub>H<sub>2</sub> assembly in a flow-channel crystal boosts C<sub>2</sub>H<sub>2</sub>/CO<sub>2</sub> separation at 348 K.

Liu, Tingting; Zhang, Mingxing; Yang, Wei; Tan, Kui; Duan, Jingui · Nat Commun · 2026

basic_science · Level V

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Abstract

Efficient adsorptive separation of acetylene (C<sub>2</sub>H<sub>2</sub>) from carbon dioxide (CO<sub>2</sub>) at elevated temperatures, which signifies saved energy consumption, remains a formidable challenge due to the thermal instability of host-guest interactions in conventional adsorbents. Inspired by the stability of linear molecular assemblies observed in polymer systems, we report a microporous crystal, NTU-103, whose one-dimensional (1D) helical flow-channel shapes adsorbed C<sub>2</sub>H<sub>2</sub> molecules into a "nanowire"-like structure stabilized by synergistic host-guest and guest-guest interactions at 348 K, while isolating CO<sub>2</sub>. This unique confinement mechanism, confirmed by varied-temperature in-situ crystallographic, infrared spectroscopic analyses and modeling calculations, enables the robust NTU-103 to achieve a high C<sub>2</sub>H<sub>2</sub>/CO<sub>2</sub> selectivity (up to 96) and cyclable breakthrough separation performance at industrially preferred conditions (348 K). This work addresses a key challenge of high-temperature separation, and provides fundamental insights into shaped gas nanostructures for advancing porous materials targeting challenging separations with minimal energy input.