Effect of modification of UiO-66 for CO2 adsorption and separation of CO2/CH4

UiO-66 and TETA/UiO-66 were synthesized by the solvothermal and impregnation methods for the study of CO2 adsorption and separation of CO2/CH4 by volumetric method. Adsorbents were characterized by X-ray diffraction (XRD), N2 adsorption-desorption isotherm (BET analyzer), FT-IR spectroscopy, Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM), and elemental analysis. All characterization results have confirmed that incorporated TETA was present and occupied pores of UiO-66. High adsorption of CO2 was obtained for 25TETA/UiO-66 compared with UiO-66 by chemical interaction between CO2 and adsorbent. Along with this, a decrease in CH4 adsorption has been observed by a change in surface area and no interaction between them. The selectivity of CO2/CH4 was higher for 25TETA/UiO-66 because of the large difference in adsorption capacities of CO2 and CH4. The heat of CO2 adsorption for TETA incorporated UiO-66 was 54.6 KJ/mol at low coverage of CO2 and CO2 adsorption capacity was constant in multiple adsorption cycles.