Adsorption of acetone and toluene by N-functionalized porous carbon derived from ZIF-8

Abstract

In this study, a N-functionalized porous carbon derived from ZIF-8 (NFPC) was prepared and applied for the gaseous acetone and toluene adsorption removal. The NFPC perfectly inherited the morphology of parent ZIF-8, posed a high specific surface area (SBET = 1228 m2·g−1), be rich in surface nitrogen functional groups, and resulting in a good dynamic adsorption of the VOCs. The NFPC-1000 exhibited the best adsorption performance of low concentration acetone and toluene, with equilibrium adsorption capacity of 203.4 and 297.1 mg·g−1 at 25 °C respectively. The acetone and toluene adsorption were spontaneously and exothermic, given the negative values of free energy (ΔG) and enthalpy (ΔH). The difference of acetone and toluene adsorption on NFPC attributed to the affinity difference (boiling point, polarity and molecular diameter), the nitrogen-containing functional groups (pyridinic-N) and the cation-π bonding. Therefore, the NFPC was found to be more favorable for aromatic compounds adsorption, the toluene adsorption of NFPC-1000 only decreased 5.3% after 6 cycles reuse, while its adsorption capacity of acetone lost more than 60%.