Enhancing the performances toward CO2 capture of MIL-96: hybridization with graphene-like material

CO2 is one of the major greenhouse gases responsible for global warming. To face the problems related to the large amount of CO2 released into the atmosphere, a number of carbon capture and storage (CCS) strategies are formulated [Yang, Environ. Sci., 2008]. Post-combustion capture offers considerable advantages because it prevents the need for substantial modifications of the combustion process and on the technologies usually used [Bhown, Environ. Sci. Technol. 2011]. Metal-organic frameworks (MOFs) are technologically advanced solid sorbents for post-combustion capture strategy [Raganati, CEJ, 2014], combining large surface area, permanent porosity, tunable pore size/functionality, selectivity, ease of handling, renewability for repeated cycles, [Stock, Chem. Rev. 2012]. MOFs are coordination polymers typically synthesized, under mild conditions, by a self-assembly reaction between metal ions (nodes) and organic ligands (linkers). This work focuses on an aluminum-based MOF known as MIL-96 in which aluminum ions are coordinated with benzene tricarboxylic acid linkers [Loiseau, JACS, 2006]. We performed the synthesis of MIL-96 as pure phase and also in presence of growing amounts of carbonaceous material in form of graphene-like layers [Alfè, App. Surf. Sci. 2015]. The pure MIL-96 phase and four MIL96/GL composites were characterized in terms of elemental composition, thermal behavior and porosity. The ability of those materials to act as CO2 sorbents was evaluated on the basis of the breakthrough curves performed in a lab-scale fixed bed microreactor. The evaluation of CO2 capture performances indicated that the composites are better CO2 sorbents compared to the pure MOF. Studies for the comprehension of the effect of the introduction of GL layers on CO2 adsorption capacity are ongoing.