A new boron cluster anion pillared metal organic framework with ligand inclusion and its selective acetylene capture properties

Abstract

The separation of acetylene (C₂H₂) from carbon dioxide (CO₂) and ethylene (C₂H₄) is important in industry but challenging due to their similar physical properties. Herein, a novel microporous boron cluster pillared metal–organic framework BSF-10 was synthesized with ligand inclusion for efficient C₂H₂/CO₂ and C₂H₂/C₂H₄ adsorption separation. The free dipyridyl ligands in the large pore reduce the porosity of BSF-10 but stabilize the framework. The available narrow pores without inclusion of ligands are suited for the accommodation of C₂H₂ by cooperative dihydrogen bonding. High C₂H₂ capacity and high C₂H₂ selectivity over CO₂ and C₂H₄ are achieved. The practical separation ability was confirmed by the breakthroughs using C₂H₂/CO₂ and C₂H₂/C₂H₄ gas mixtures with good recyclability. The dynamic separation factor of 2.8 for the equimolar C₂H₂/CO₂ mixture is comparable to those of many benchmark materials.