Tuning CO2 Capture and Conversion with Metal–Organic Frameworks Crystallized in Aqueous Graphene Oxide Suspensions

Abstract

[EN]We present a green procedure for the synthesis of metal-organic frameworks (having either Zn, Ni and Co) in graphene oxide aqueous suspension (obtained with graphitized or non-graphitized carbon nanofibers) avoiding organic solvents and high temperatures. The materials were thoroughly characterized using XRD, SEM, N2/CO2-physisorption, Raman and XPS spectroscopies, and TGA. Our results demonstrate that the nature of the metal (electronegativity) and graphene oxide (oxygen-containing defects) are key in the size, porosity and defectivity (free non-coordinated linkers and open metal sites) of the MOF and significantly affect their CO2 adsorption energy (up to 6 kJ·mol-1 increase), uptake (up to 5·mmolCO2·g-1 increase) and catalytic activity (up to 35% rate increase with respect to bulk MOFs) in the solvent-free ambient pressure CO2 cycloaddition to epoxides.