Volatile organic compounds (VOCs) are hazardous air pollutants, and the development of sustainable carbon adsorbents with high capacity, humidity tolerance, and regenerability remains an important challenge. Herein, N-doped hierarchical porous carbons were synthesized from liquefied wood via melamine-assisted carbonization followed by a Na2CO3/K2CO3 activation strategy. By adjusting the Na/K ratio, the pore architecture and surface nitrogen configuration of the resulting carbons were systematically tuned. Among the prepared samples, BPC-Na5K5 exhibited the most balanced textural and surface properties, with a high specific surface area (2338 m2/g), a large micropore volume (1.117 cm3/g), and a substantial mesopore contribution (0.464 cm3/g). Under dynamic adsorption conditions, BPC-Na5K5 delivered a saturated toluene adsorption capacity (qe) of 592 mg/g at 25 °C and 1000 mg/m3 and retained 94% of its dry-state qe at 50% relative humidity, together with good regeneration stability. Binary VOC adsorption tests further demonstrated preferential toluene retention over acetone, ethyl acetate, and cyclohexane, accompanied by roll-up of the weaker adsorbates. Comparative analysis suggests that the superior performance arises from the cooperative effect of micropore-dominated adsorption space, mesopore-assisted mass transport, and surface chemistry that modulates aromatic VOC affinity. This work provides a practical mixed-carbonate tuning strategy for systematically optimizing hierarchical porosity and nitrogen configuration in liquefied-wood-derived porous carbons toward efficient VOC adsorption and removal.
Jiang et al. (Tue,) studied this question.