Novel Hierarchical Meso-Microporous Hydrogen-Bonded Organic Framework for Selective Separation of Acetylene and Ethylene versus Methane

Abstract

Herein we construct a novel three-dimension (3D) hydrogen-bonded organic framework (PFC-2) with a hierarchical meso-microporous structure, which possesses the largest open channels relative to all known HOFs and exhibits highly selective separation of acetylene and ethylene versus methane at ambient atmosphere. Comparison on the adsorption behaviors of PFC-2 and an analogue structure PFC-1 clearly shows that the extensively existed unpaired hydrogen bond acceptor C═O groups in PFC-2 dramatically increase the affinity between gas molecules and frameworks, resulting in high isosteric heats of adsorption ( Q_st) and better selectivity toward C₂ hydrocarbons to methane. The study presented here demonstrated an effective strategy to optimize gas adsorption/separation performance of HOF materials.