Carbon dioxide adsorption performance of ultramicroporous carbon derived from poly(vinylidene fluoride)

Abstract

This study examined the properties of ultra-microporous carbon synthesized by the pyrolysis of poly(vinylidene fluoride) as a function of the heat-treatment temperature, and evaluated the CO2 adsorption capacity by pressure swing analysis. X-ray photoelectron spectroscopy confirmed the specific elements of the heat-treated carbon (HTC) surfaces. The textural properties were analyzed using N2 adsorption isotherms at 77K. The CO2 adsorption capacity was measured by CO2 isothermal adsorption at 298K and under increasing pressure up to 100kPa. The CO2 adsorption capacity increased with increasing heat-treatment temperature to 873K (HTC-873, 155mg/g), and then decreased at 973K (HTC-973), which correlated with their micropore volume. Interestingly, HTC-773 with a smaller pore size had higher CO2 adsorption capacity than HTC-873 at pressures up to 30kPa. This results show that the CO2 adsorption capacity at a certain pressures (in particular <30kPa) is strongly affected by the pore size of the HTC samples but not by the micropore volume or specific surface area.