铁系MOFs室温甲醛去除性能与机理研究

Owing to the many advantages of Fe-based MIL series metal-organic frameworks (Fe-MOFs), such as high specific surface area, large pore volume, abundant and convenient host-guest modifications, etc., Fe-MOFs hold great potentials for significant applications in the fields of indoor air purification. Up to now, the available Fe-MOFs materials for room temperature formaldehyde removal with high removal efficiency, mineralization efficiency and cycling stability is limited, and the formaldehyde removal mechanism on Fe-MOFs materials is not clear. To meet these limitations, in this project, we aim to exploit novel Fe-MOFs materials for highly efficient removal of formaldehyde from air at room temperature. Starting from design and preparation of novel Fe-MOFs materials, the key parameters for tuning microstructures (including crystallographic structure, porous structure, morphology, etc.) will be deeply disclosed, the new modification methods for functionalization of Fe-O clusters and ligands will be developed, and loading routes for hybridization with noble metal nanoparticles will be optimized, and thus, a series of novel Fe-MOFs materials with tuned compositions and structures will be constructed, with aim to significantly enhance the removal efficiency, mineralization efficiency and cycling stability for removing formaldehyde. Based on systematical characterization and analyses of the composition, structure and physicochemical properties of Fe-MOFs materials, the structure-activity relationships will be established, the dominative active centers, formaldehyde removal pathways and mechanism on Fe-MOFs system will be clarified, and especially, the synergetic effects of adsorption and photo-thermo-catalysis processes will be illustrated. This project will provide new ideas for exploiting highly efficient formaldehyde removal materials, will enrich the theory guiding room temperature formaldehyde removal, and will greatly promote the development of advanced technology for indoor air purification.

以Fe基MIL系列为代表的金属有机框架（Fe-MOFs）材料，由于高比表面积、大孔体积、丰富便捷的主客体改性等优点，有望在室内空气净化领域发挥重要作用。针对室温甲醛净化领域高去除率、高矿化率与高稳定性材料缺乏，以及Fe-MOFs材料甲醛去除机理不清楚的现状，本项目拟从新型Fe-MOFs的设计制备出发，深入挖掘晶体结构、孔结构与形貌等微结构调控关键参数，发展铁氧簇与配体功能化改性方法，优化贵金属复合负载方法，构建一系列组成与结构可控的Fe-MOFs新体系，显著改善Fe-MOFs新体系的甲醛去除率、矿化率和稳定性。结合组成、结构和物性表征分析，建立构效关系模型，揭示Fe-MOFs新体系的关键活性位点与甲醛去除过程机理，阐明吸附-光热催化过程协同作用机制。本项目将为开发高效室温甲醛净化体系提供新思路，丰富室温甲醛净化理论，对推动室内空气净化技术的发展具有重要指导意义。

室温催化氧化（RTCO）技术是最具发展前景的室内甲醛净化技术之一，对改善室内空气质量与保障居民健康具有重要意义。本项目针对室温催化氧化甲醛（HCHO）效率偏低、矿化率不高、稳定性欠佳的关键技术难题，发展典型MOFs材料的缺陷工程、配体调制与贵金属负载方法，构建富含配位不饱和位点（CUSs）的多功能催化活性中心，协同调控分子氧和水分子的吸附活化，显著提高HCHO去除率、矿化率与稳定性，为发展实用RTCO室内甲醛净化技术提供科学依据与技术支撑。.主要研究成果如下： .（1）制备了富含FeIII/FeII-CUSs的MIL-88B(Fe)、富含Zr-CUSs-Ptδ+的Pt/UiO-66(Zr)等一系列具有优异室温O2活化效率与HCHO催化氧化性能的RTCO材料新体系。.（2）FeIII/FeII-CUSs、Zr-CUSs-Ptδ+等多功能活性中心，既有助于调控表面酸碱性，又增强O2活化产生•O2-、1O2等高活性氧物种，展示了酸碱催化与氧化还原催化在HCHO氧化转化中的协同效应，显著改善静态与动态反应系统中HCHO去除率，矿化率与稳定性。.（3）在上述HCHO→CO2研究基础上，本项目尝试开发Ti3C2Tx/TiO2肖特基结等双功能复合光催化剂、胺基化BDC配体修饰Bi-MOFs衍生的宽电位工作窗口与宽pH值工作窗口电催化剂，构建新型“甲醛氧化降解与CO2转化利用”耦合光/电催化反应系统，驱动人工碳循环利用。