Hierarchical porous carbon as a highly efficient adsorbent for toluene and benzene

With the development of economy and the improvement of environmental protection awareness, more pollutants such as the volatile organic compounds (VOCs) need be controlled from coal-combustion flue gas. In this work, a biomass-derived nitrogen-doped hierarchical porous carbon (NHPC) used as a versatile sorbent material, and the effect that the hierarchical porous structure (micro-meso-macropores) and the surface nitrogen functional groups of the NHPC have on the adsorption of two VOCs (toluene and benzene) have been studied. The optimum calcination temperature is 900 degrees C for both NHPC and HPC (none-doped hierarchical porous carbon), which have the highest specific surface area and micropore volume. The NHPC presents a higher adsorption capacity for toluene (272 mg/g) and benzene (151 mg/g) than those of HPC and AC. By contrasting the NHPC and HPC, the facilitation of NHPC surface nitrogen species on adsorption capacity can be predicted. In the case of HPC and AC, it is believed that the 3D-interconnectd framework also has a unique acceleration effect on adsorption rate. The upgrading of NHPC adsorption performance depends on both nitrogen content and pore structure. Based on the facile preparation process and high adsorption capacity, the biomass-derived hierarchical porous carbon could have promising widespread applications in removing the organic pollutants from coalcombustion flue gas.