The pore structure evolution and stability of mesoporous carbon FDU-15 under CO2, O2 or water vapor atmospheres

Mesoporous carbons FDU-15 with ordered hexagonal structure were prepared by using triblock copolymer Pluronic F127 as a template and resol as a carbon precursor via evaporation induced organic–organic assembly method. The pore structure evolution and stability of FDU-15 functioned with the treatment temperature and time were systematically investigated in CO2, O2 or water vapor atmospheres. A variety of techniques such as powder X-ray diffraction (XRD), nitrogen sorption and transmission electron microscopy (TEM) were used to characterize the thermal stability of the carbon mesostructure. N2 sorption measurements show that the activation process can simply increase the specific surface area and pore volume of the mesoporous carbons. The effect of structural regularity, pore size, meso- or microporosity, and wall thickness on the thermal stability at different treatment temperature and time was discussed. The results show that mesoporous carbon FDU-15 materials after the carbonization at 900 °C have a good thermal stability under CO2 at 750 °C, O2 at 350 °C and water vapor at 800 °C for at least 3 h. Nevertheless, CO2, O2 or water vapor develops the pore system through different ways. For CO2, the thermal treatment leads to large mesopore volumes while the micropores are slightly increased during the carbon burn-off. Different from CO2, water vapor activation renders a continuous increase of micropore volumes as well as the total pore volumes with increasing the carbon burn-off. Under O2-treatment at 350 °C, the ordered mesostructures can be rapidly destroyed due to the fast burning reactions of oxygen with mesoporous carbons.