Dynamic Adsorption of Toluene on Hierarchical Porous Carbons with Varying Pore Structure

Hierarchical porous carbon material(MMC)was successfully fabricated via hard template synthesis method by carbonization of furfury alcohol within the template(MCM-41).The prepared MMC was studied with characterization methods including scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption analyses,and infrared spectral analysis(FTIR).To investigate kinetics of toluene adsorption of hierarchical porous carbon materials,the adsorption performances of these carbon samples with varying pore structure(MC-1,MMC,MMHPC)were analyzed via dynamic adsorption.And the Langmuir model and Freundlich equation were employed to correspond with adsorption isotherms to study the adsorption mechanism.The experimental results demonstrate that the Langmuir model is more appropriate to describe the adsorption process.The capacities of toluene adsorption follow the order of MMC<MMHPC(micro-meso hierarchical porous carbon)<MC-1(microporous carbon).MC-1 has satisfactory absorption performance due to its large pore volume and high ratio of micropores.MMHPC has excellent toluene adsorption performance for proper amounts of surface oxygen containing groups.Long saturation time,interconnected hierarchical pore channels,and large specific surface area make MMC also a promising material for VOCs treatment.These data reveal that the pore channel structure,rational pore distribution,high surface area and reasonable amounts of surface oxygen groups are the main factors contributed to excellent toluene adsorption performance,which proposes theoretical basis for hierarchical porous carbon materials to further engineering application.