Enhanced CO2 Adsorption on Nitrogen-Doped Porous Carbons Derived from Commercial Phenolic Resin

The CO2-capture potential of porous carbons that have been derived from phenolic resin and doped with nitrogen was assessed in this work. Using carbonized commercial phenolic resin as carbon precursors, a series of carbons have been synthesized using urea modification and KOH activation under different conditions. The activation temperature and mass ratio of KOH to precursor affected the CO2 uptake capacity. These phenolic-resin-derived carbons show high CO2 capture capacity, up to 4.61 mmol/g at 25 °C and 7.13 mmol/g at 0 °C under atmospheric pressure. The sample prepared under relatively mild conditions, i.e., activation temperature of 600 °C and mass KOH/precursor of 3, demonstrated the maximum CO2 uptake capacity under ambient conditions. A systematic study shows that the synergetic effects of narrow microporosity and nitrogen content determine the sorbents' capability to capture CO2. In addition, the pore size and the narrow micropores' distribution affect the CO2 adsorption capacity of this series of porous carbons. Moreover, these resin-derived carbons show other superior CO2 capture properties such as fast sorption kinetics, high CO2/N2 selectivity, moderate heat of adsorption, stable recyclability, and high dynamic CO2 capture capacity.