Wang Shanshan, Hu Jianggen, Li Licheng, Zuo Songlin
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, P.R. China.
ACS Omega. 2024 Sep 19;9(39):40368-40377. doi: 10.1021/acsomega.4c02262. eCollection 2024 Oct 1.
The presence of water vapor influences the adsorption equilibrium and kinetics of volatile organic compounds (VOCs) in porous materials. By combination of breakthrough experiments and molecular simulations, the competitive adsorption mechanisms of water vapor and acetone on activated carbon with different textures and surface chemical properties at different humidity levels were investigated. Adsorption capacity decreases with increasing relative humidity owing to the formation of preferential adsorption sites between water and the activated carbon surface, while the adsorption rate initially increases and then decreases with increasing relative humidity. Experimental and simulation results revealed that the existence of a small amount of water changed the pore size distributions of activated carbon, thereby promoting the diffusion of acetone molecules. As the relative humidity increased, a portion of the acetone dissolved in water, resulting in a reduction in the adsorption rate. The response of different functional groups to relative humidity was further clarified by molecular simulation. Activated carbons with a high electrostatic interaction with acetone were less affected by humidity and thus exhibit greater potential as adsorbents.
水蒸气的存在会影响多孔材料中挥发性有机化合物（VOCs）的吸附平衡和动力学。通过突破实验和分子模拟相结合的方法，研究了在不同湿度水平下，水蒸气和丙酮在具有不同织构和表面化学性质的活性炭上的竞争吸附机制。由于水与活性炭表面之间形成了优先吸附位点，吸附容量随相对湿度的增加而降低，而吸附速率最初随相对湿度的增加而增加，然后降低。实验和模拟结果表明，少量水的存在改变了活性炭的孔径分布，从而促进了丙酮分子的扩散。随着相对湿度的增加，一部分丙酮溶解在水中，导致吸附速率降低。通过分子模拟进一步阐明了不同官能团对相对湿度的响应。与丙酮具有高静电相互作用的活性炭受湿度影响较小，因此作为吸附剂具有更大的潜力。
