Enhanced CO2 Adsorption and CO2/N2/CH4 Selectivity of Novel Carbon Composites CPDA@A-Cs

Abstract

New carbon composites (CPDA@A-Cs) were successfully prepared by carbonizing and activating the polydopamine (CPDA) and asphalt-based carbons (A-Cs) for CO2 capture and separation. The resulting CPDA@A-Cs were characterized, and the CO2, N2, and CH4 adsorption separation performances of CPDA@A-Cs were investigated systematically. Results showed that CPDA@A-Cs exhibit a high Brunauer–Emmett–Teller specific surface area of 2031 m2/g and a high total pore volume of 0.81 cm3/g, respectively. Boehm titration showed that the introduction of CPDA made the basic site concentration of CPDA@A-Cs increase in comparison with that of the parent A-C, and X-ray photoelectron spectroscopy analysis indicated that the N-containing groups mainly consisted of pyridinic N and pyridonic N. At the ambient pressure, the CO2 uptakes of CPDA@A-Cs amounted up to 6.89 mmol/g at 273 K and 4.05 mmol/g at 298 K, increasing by 34% compared with the parent A-C, and much higher than that of the most reported carbonaceous materials under th...