A Microporous Graphitized Biocarbon with High Adsorption Capacity toward Benzene Volatile Organic Compounds (VOCs) from Humid Air at Ultralow Pressures

Adsorption studies of vaporous benzene and toluene on a novel microporous graphitized biocarbon material (MGBC) were investigated in this study. The MGBC has high surface area (>2080 m2/g) and uniform microporosity (6.8–8.8 A). The adsorbed amounts of benzene and toluene on the MGBC are ∼3–5 times higher than those on zeolites and some metal-organic framework (MOF) adsorbents (i.e., MIL-101, HKUST-1, and UIO-66) at 80 Pa. Results of the desorption activation energy and isosteric heat indicate a strong affinity of the MGBCs for benzene/toluene molecules, because of its uniform micropores size and graphitic N/C in MGBC structure. Moreover, the MGBC possesses a hydrophobic character, and thus leads to a preferential adsorption for toluene over H2O. Therefore, the MGBC shows a much higher working capacity for toluene than MIL-101(Cr) and commercial activated carbons (ACs) in moderate humidity.