By employing SBA-15 as a hard template and boric acid as a pore-expanding agent, we synthesized a series of tunable ordered mesoporous carbons (OMCs) with high specific surface areas and large pore volumes. The synthesized OMCs were used as adsorbents for benzene disposal to explore the influence of pore width on the adsorption of benzene. The XRD and nitrogen adsorption results revealed that the pore sizes of OMCs were contracted at certain values, within the range of 3.47.7 nm. The adsorption results for benzene on the OMCs showed that there was a gradual decrease in adsorption potential as the pore size of the adsorbent material increased. In addition, an evaluation of the dynamic adsorption of benzene per unit surface area indicated that the adsorption behaviors were strongly influenced by the pore width of the adsorbent material.