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

Abstract

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.