High and selective CO2 uptake in a nitrogen-rich pillar-layered metal organic framework

Abstract

A nitrogen-rich pillar-layered metal organic framework, Co(Imda)(4,4′-bpy), comprising cobalt(II) clusters interconnected by imidazole-4,5-dicarboxylic acid and 4,4′-bipyridyl groups was synthesized, and characterized by powder X-ray diffraction, N₂ adsorption–desorption measurements, thermogravimetric analysis, and scanning electron microscopy. This material was firstly investigated for CO₂ capture. It exhibited several outstanding attributes as a CO₂ adsorbent: high CO₂ uptake (135 mg g⁻¹ at 298 K, 1 bar), good separation selectivity against N₂ (CO₂/N₂ selectivity of ca. 18 at 298 K, 1 bar), fast adsorption kinetics (saturation within 10 min), easy regeneration (298 K, argon purge) and excellent stability in moisture and during consecutive adsorption–desorption cycles.