Surface functionalization methodologies on activated carbons and their benzene adsorption

The present work reports the effect of different functionalization methodologies on surface modification of porous carbon and its efficacy for benzene adsorption. The virgin and surface-modified adsorbents were characterized by FTIR, N(2)sorption analysis, SEM, and Boehm titration. The adsorption isotherms were measured at different temperatures using a highly sensitive magnetic suspension microbalance. At lower benzene concentration, the virgin carbon was found to possess reasonable adsorption capacity, while at higher benzene concentration, the surface-modified carbon tends to perform better. The maximum benzene adsorption capacity at 25 degrees C and vapor pressure of 90 mbar is as follows: 467 mg/g (NORIT-AC), 227 mg/g (AC-APS (1 M)), 388 mg/g (Norit-AC-HT), 492 mg/g (AC-HNO3), and 531 mg/g (AC-H2SO4).