BTC-based metal-organic frameworks: correlation between relevant structural features and CO2 adsorption performances

Fossil fuels combustion is one of the major sources of free CO2 so far. To mitigate the consequent drawbacks on global warming, actions aimed to carbon capturing and sequestration (often abbreviated as CCS) are still a priority task. A possible approach, in which huge efforts of dedicated scientific research are currently focused, is the development of innovative materials able to capture CO2 more efficiently in operating conditions typical of a flue gas. The combined favorable properties of large surface area, permanent porosity and tunable pore size/functionality, have enabled metal-organic frameworks (MOFs) as ideal candidates for CO2 capture in post-combustion configuration. At the present, the volumetric capacity of MOFs toward CO2 is rarely studied and breakthrough experiments of simulated flue gas to evaluate CO2 selectivity are not always performed. In this work we selected three 1,3,5-benzenetricarboxylic acid (BTC) based MOFs (Zn-HKUST-1, Al-MIL-96 and Fe-MIL-100) differing in morphology and textural properties and we characterized them through breakthrough experiments in order to assess the influence of structural/textural properties and the morphology of MOFs on CO2 sorption capacity.