KIT-6 Üzerinde CO2 Adsorpsiyon Davranışı ve Kinetiği Üzerine Bir Çalışma

Abstract

KIT-6 mesoporous silica has been used in catalysis, nano containers, adsorption and drug delivery applications due to its original three dimensional channel network. Typically, KIT-6 is prepared from triblock copolymers as the template directing agents under acidic conditions. In this article, KIT-6 was successfully synthesized via partitioned cooperative self-assembly method. The synthesized sample was characterized using X-ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA) and N2 adsorption/desorption. The characterization methods demonstrated that the synthesized sample is ordered KIT-6 mesoporous silica with a high surface area (605.93 m2 g-1), pore volume (0.58 cm3 g-1), and good thermal stability. The CO2 adsorption studies of the sample were performed at different temperatures (25, 75 and 100°C). The maximum adsorption capacity (0.65 mmol g-1) was observed at 25°C adsorption temperature. In addition, it was determined that the adsorption capacity of KIT-6 decreases with increasing adsorption temperature. This study also presents the investigation of the CO2 adsorption kinetics on KIT-6 using the first order and the second order models. The kinetic data for the CO2 adsorption on the sample conformed to the second order model. The activation energy (Ea) was calculated as 18.75 kJ mol-1 from Arrhenious plot for CO2 adsorption on KIT-6 mesoporous silica. Moreover, the regenerability and cyclic stability of KIT-6 mesoporous silica was determined using TG/DTA analysis. From the analysis results, it was clearly seen that the ordered mesoporus silica has perfect cyclic stability of 94% after 4 adsorption/desorption cycle, which implies that the synthesized KIT-6 could possibly used as an adsorbent in the CO2 adsorption.