三维有序多孔La-BiOBr-MnOx/BCF增效低温等离子体净化气态二甲苯的基础研究

Volatile Organic Compounds (VOCs) are considered as the main factors causing air pollution, and they are also the precursor of PM2.5 generated. VOCs had significant negative effect on the air quality and human health. Non-thermal plasma(NTP) is a promising technology applied in the field of air pollutants purification. However, the low energy utilization efficiency, bad product selectivity and a large number of byproducts generated including ozone are the main drawbacks of NTP technology. In this project, Para-Xylene (PX) is selected as the representative of VOCs, and ordered macroporous biomass carbon foam (BCF) doped with La-BiOBr and MnOx will be filled in the discharge area of NTP to improve the degradation efficiency of PX by the combination of adsorption and double catalytic system. The basic research and discussion on scientific problems on synergistic effect for purification of PX will be carried out as follow: (1) La-BiOBr-MnOx/BCF will be controllably prepared from waste biomass, and then the influence of key factors on the physical and chemical properties such as microscopic pore structure, adsorption and catalytic activity of BCF doped with La-BiOBr-MnOx need to be demonstrated. (2) study on the optimization of technical parameters and the comparison of PX removal efficiency in the synergistic system; (3) study on the degradation mechanism of PX and synergistic mechanism of the system; (4) evaluation of inactivation, stability and reproducibility of the functional materials. The successful completion of this project will effectively solve the application bottleneck problem of NTP, and provide theoretical basis and technical reference for high-efficient purification of industrial waste gas containing VOCs.

挥发性有机物(VOCs)是大气污染物的重要来源，也是形成PM2.5的重要前体物，严重影响空气质量和危害人体健康。低温等离子体(NTP)是一种极具应用前景的VOCs净化技术，然而，NTP技术存在能源利用率低、产物COx选择性差及产生臭氧二次污染等应用瓶颈问题。本项目以典型VOCs对二甲苯(PX)为目标物，在NTP放电区域内填充掺杂La-BiOBr和MnOx的有序多孔生物质泡沫炭(BCF)，通过吸附+双催化体系协同增效NTP对PX的净化，系统开展相关基础研究和关键科学问题探讨：(1)关键因子对可控制备La-BiOBr-MnOx/BCF的理化性质和吸附/催化活性的影响；(2)协同体系下技术参数的优化及对PX去除效果的对比研究；(3)PX的降解机理及体系的增效作用机制；(4)功能材料的失活、稳定性及重复性。本项目的顺利完成将为有效解决NTP应用瓶颈问题和工业VOCs高效净化提供理论依据和技术参考。

挥发性有机物(VOCs)是大气污染物的重要来源，低温等离子体(NTP)是一种极具应用前景的VOCs净化技术。本项目针对NTP技术在处理VOCs过程中存在的能源利用率低、产物COx选择性差及产生臭氧副产物等应用瓶颈问题，设计了介质阻挡放电NTP气相降解反应器，并通过构建炭基吸附+铋系/锰氧化物双催化体系对NTP放电区域发射的紫外光和可见光以及生成的臭氧加以利用，协同增效气态二甲苯的降解。这些研究工作有力地促进NTP与催化剂协同应用脱除VOCs的发展。主要研究如下：(1)以废弃生物质为原材料，通过液化、树脂化、水热反应和热活化等技术耦合制备出成型多孔炭捕集材料，并通过羧基化联合离子交换技术实现了对炭材料孔径的调控，明确了孔径变化对二甲苯吸附性能的影响；(2)将稀土金属镧掺杂在BiOBr中，并将La-BiOBr与臭氧催化剂MnOx和多孔炭材料相结合，优化制备了1%La-BiOBr@MnOx/BC复合材料；(3)揭示了复合材料与NTP之间的协同促进作用，研究表明放电区域内添加复合材料有助于提升NTP去除二甲苯的效果。在输入功率40W、二甲苯初始浓度17.32mg/L、气体流速0.8L/min、放电区域内添加8.0g复合材料时，与单一NTP降解相比，反应5min和10min二甲苯去除率分别提高了25.8%和20.9%，反应20min后二甲苯去除率可达100%；(4)阐明了吸附富集和光催化氧化、催化臭氧化对NTP去除二甲苯的协同增效作用机制，复合材料多次使用后仍能保持良好的催化活性和稳定性。共发表SCI学术论文6篇，其中影响因子大于6的3篇；申请国家发明专利2件，授权实用新型专利2件，取得了预期的研究成果。为有效解决NTP技术的应用瓶颈问题和工业排放VOCs的高效净化提供了理论依据和技术参考。