A Robust Squarate-Cobalt Metal-Organic Framework for CO 2 /N 2 Separation.

The separation of CO ₂ from the industrial post-combustion flue gas is of great importance to reduce the increasingly serious greenhouse effect, yet highly challenging due to the extremely high stability, low cost, and high separation performance requirements for adsorbents under the practical operating conditions. Herein, we report a robust squarate-cobalt metal-organic framework (MOF), FJUT-3, featuring an ultra-small 1D square channel decorated with -OH groups, for CO ₂ /N ₂ separation. Remarkably, FJUT-3 not only has excellent stability under harsh chemical conditions but also presents low-cost property for scale-up synthesis. Moreover, FJUT-3 shows excellent CO ₂ separation performance under various humid and temperature conditions confirmed by the transient breakthrough experiments, thus enabling FJUT-3 with adequate potentials for industrial CO ₂ capture and removal. The distinct CO ₂ adsorption mechanism is well elucidated by theoretical calculations, in which the hierarchical C···O _{CO 2} , C-O···C _{CO 2} , and O-H···O _{CO 2} interactions play a vital synergistic role in the selective CO ₂ adsorption process.