Porous carbon for oxygenated and aromatic VOCs adsorption by molecular simulation and experimental study: Effect pore structure and functional groups

It is very difficult to design and prepare carbon-based adsorbents due to the wide variety and great differences in physical and chemical properties of VOCs. Here, representative oxygenated VOCs (methanol, ethanol and acetone) and aromatic VOCs (benzene, toluene and p-xylene) were selected. The influences of pore sizes and nitrogen/oxygen groups of porous carbon on different VOCs adsorption were investigated by molecular simulation. The results display that for oxygenated VOCs, the adsorption capacity is determined by micropores and functional groups at relatively low pressure, while the adsorption capacity mainly depends on pore structure at relatively high pressure. For aromatic VOCs, the influence of nitrogen and oxygen groups on adsorption capacity is limited, and the adsorption capacity is determined by the pore structure. Then, a series of nitrogen and oxygen-doped porous carbon (NOCs) were prepared. Taking methanol and benzene as examples, the effects of heteroatoms and pore size on VOCs adsorption were studied. The experimental results were consistent with the theoretical calculation. The above results reveal the influence of functional groups and pore structure on the adsorption properties of VOCs from the perspective of experiment and theoretical calculation, which provides a basis for the further design and development of carbon-based VOCs materials.