Large carbon dioxide adsorption in ZTC at medium pressure: Effects of surface functionalization

Zeolite-Template-Carbon is a new class of porous ordered carbon-based materials synthetized using 3-D zeolites as a template, then for these features have been investigated CO2 capture. This work presents the synthesis and characterization of ZTC on beta-type zeolite with a tuning-surface properties procedure resulting from different post-synthesis strategies aimed to tune the surface O-containing functional groups. It shows how a suitable micropore size distribution, a high specific surface area and a pore wall functionalization could maximize the reversible CO2 adsorption. Structural, chemical and morphological characterization has been obtained by X-ray diffraction, Thermo-gravimetric analysis, Raman/FT-IR spectroscopy, Branauer-Emmett-Teller analysis and scanning electron microscopy, while adsorption properties were investigated with Sievert's-type apparatus. XRD patters showed good replica of 3-D zeolite frameworks without presence of graphene and FT-IR spectroscopy indicated the presence of different carbon-oxygen functional groups. Adsorption measurements, at room temperature and pressure range 0–15 bar, showed a reversible CO2 uptake of 76.5 wt%. Furthermore, using deconvolution approach, a deep Raman spectroscopy analysis allowed us to assess the change in the structural order and in oxygen atomic coordination induced by post-synthesis treatment in correlation with the adsorption capacity. Post-synthesis treatments induced structure modification elucidated by evidence of an increased order of the porous structure and variation of the amorphous carbon fraction.