近日，广东工业大学环境健康与污染控制研究院、环境科学与工程学院安太成教授团队题为《Experimental and DFT investigations on adsorption–regeneration performance and deactivation mechanism over engineered carbon fiber: role of pore structure and functional groups》的学术论文在Environ. Sci.: Nano (2023,10, 2790-2798) 杂志上接受发表。论文的第一作者为张卫平副教授，通讯作者为安太成教授。该论文主要针对工业过程VOCs吸附剂吸附容量低及易失活的问题，通过详细阐述含氧类VOC（OVOC）的吸附容量和吸附强度与多孔碳纤维吸附剂的孔结构和官能团的关联规律，并通过实验和DFT理论计算相结合，详细探究了OVOC在多孔碳纤维上吸附-脱附机制、诱发吸附剂失活的关键原因等。有望为工业有机废气处置过程中经济高效的含氧VOCs的回收材料的精细化设计及高值VOCs的资源化利用提供理论指导。

论文网址： https://doi.org/10.1039/D3EN00443K

 

多孔碳吸附技术是一种有前景的经济高效的挥发性有机化合物（VOCs）回收技术。然而，基于孔结构和官能基团决定的多孔碳吸附剂的失活机制仍不清楚，这严重限制了它们在VOCs吸附回收、资源化利用或污染控制中的应用。本研究中详细探究了改性多孔碳纤维上孔结构和官能基团与乙酸乙酯（EA）吸附-再生之间的关联机制。实验和DFT理论计算结果表明：微孔结构是吸附容量的主控因素，特别是微孔的物理吸附作用决定乙酸乙酯(EA)的吸附容量，同时适当的碱性基团有利于增强EA与多孔碳的化学吸附作用。然而，EA与多孔碳之间的强化学吸附作用使得完全再生变得异常困难（在进行6次吸附-再生循环后多孔碳仅能保留81.5%的吸附容量）。通过XPS的半定量研究和GC-MS转化中间产物分析表明：多孔碳吸附剂的失活与EA的热化学转化密切相关，主要基于EA与吸附剂界面之间的强化学吸附作用，导致EA的热化学转化为高沸点炭质导致堵塞孔结构并占据界面活性位点，进而诱发吸附剂失活。本论文的结果有望为高效经济VOCs吸附剂的精细化设计和性能调控提供一定的启示和理论指导。

图文摘要：

英文摘要：

Technology based on adsorption of porous carbon is a promising and cost-effective strategy for the recovery of high-value volatile organic compounds (VOCs) or removal of worthless VOCs. However, the deactivation mechanism of porous carbon adsorbents determined by pore structure and functional groups is not clear. This knowledge gap limits their application in the resource utilization or pollution control of VOCs. We investigated the effect of the pore structure and functional groups in relation to adsorption and regeneration of ethyl acetate (EA) over engineered carbon-fiber adsorbents. Experimental and density functional theory (DFT) results indicated that appropriate basic groups were beneficial for EA adsorption, and the physisorption of micropore structure contributed more to the adsorption capacity. However, the strong chemisorption between EA and adsorbents hampered complete regeneration (only 81.5% capacity retention over six cycles of optimal adsorbents). Semi-quantitative methods and identification of intermediates confirmed that deactivation of porous carbon adsorbents was closely related to EA conversion due to strong chemisorption between EA and the adsorbent interface, which resulted in blockade of the pore structure and occupation of interfacial active sites. Our results may guide the design of highly efficient and economic adsorbents with complex micro-interfaces for recovery of high-value VOC.

项目资助：该研究工作得到了国家自然科学基金（42007327, 42007315和22076028），广东省重点研发计划项目（2022-GDUT-A0007），广东省本土创新团队（2017BT01Z032），广东省基础与应用基础研究项目（2019A1515110298和2021A1515010278），广东省普通高校重点实验室项目（2018KSYS007）等项目的支持。