Robust Two-Dimensional Hydrogen-Bonded Organic Framework for Efficient Separation of C1–C3 Alkanes

Separating natural gas to obtain high-quality C1–C3 alkanes is an imperative process for supplying clean energy sources and high valued petrochemical feedstocks. However, developing adsorbents which can efficiently distinguish CH4, C2H6, and C3H8 molecules remains challenging. We herein report an ultra-stable layered hydrogen-bonded framework (HOF-NBDA), which features differential affinities and adsorption capacities for CH4, C2H6, and C3H8 molecules, respectively. Breakthrough experiments on ternary component gas mixture show that HOF-NBDA can achieve efficient separation of CH4/C2H6/C3H8 (v/v/v, 85/7.5/7.5). More importantly, HOF-NBDA can realize efficient C3H8 recovery from ternary CH4/C2H6/C3H8 gas mixture. After one cycle of breakthrough, 70.9 L·kg–1 of high-purity (≥ 99.95%) CH4 and 54.2 L·kg–1 of C3H8 (purity ≥99.5%) could be obtained. Furthermore, excellent separation performance under different flow rates, temperatures, and humidities could endow HOF-NBDA an ideal adsorbent for the future natural gas purification.