多价态金属复合的钙钛矿型类芬顿催化降解水中有机污染物的研究

Several heterogeneous Fenton catalysts, such as layered birnessite-type manganese oxides (Na-OL-1), Cu-doped Bi2O3 (Bi1.5Cu0.5O3) and LaTiO3 perovskite (LaTi0.4Cu0.6O3) were successfully prepared. These catalysts exhibited high efficiency for the Fenton degradation of dyes and pharmaceuticals in water. Moreover, the catalytic reaction could be performed without UV, ultrasonic, and microwave et al. At present, 7 SCI papers and 1 paper in Chinese core periodical have been published and the other 4 manuscripts are also under review. Based on the National Science Foundation and the relevant experience in the catalytic removal of organic pollutants, the aim of this object is to develop a heterogeneous Fenton catalyst, perovskite-like oxides doped by transitional metals. The interfacial electron transfer within the catalyst could be greatly accelerated via change of the elements’ oxidation state and regulation of the number of lattice oxygen defect which leads to more ?OH generation as a result of H2O2 decomposition. Moreover, the catalyst could be recovered by magnetic separation via the introduction of magnetic elements. The Fenton degradation of typical pollutants such as pharmaceutical and herbicides in water will be investigated. Besides, the mechanism of H2O2 decomposition and the ?OH generation on the surface of the catalyst and the effect of electron transfer on the pollutants degradation would be focus of this object. Finally, the operation conditions should be optimized based on the water quality characteristics, and try to devise a Fenton reactor, resulting in the development of heterogeneous Fenton catalysis.

成功制备了高活性多相芬顿催化剂——层状锰氧化物、铜掺杂氧化铋和镧铜掺杂的钙钛矿型复合氧化物。上述材料在无紫外光、超声和微波等辅助下，均能强化过氧化氢分解产生?OH等自由基，高效降解水中的染料和医药品化合物；已经接收和发表7篇SCI和1篇中文，另有4篇SCI文章在审稿过程中。在上述工作基础上，本项目提出研制多价态金属复合的钙钛矿型类芬顿反应催化剂，通过A、B位元素的取代和掺杂，形成多价态金属共存、控制晶格氧缺陷数目，加强界面电子转移，强化过氧化氢分解产生?OH等活性物种；通过引入磁性金属组分使得催化剂具有一定磁性，可以磁力回收。重点处理饮用水源中典型的难降解有机物如医药品、农药等，研究催化剂催化分解过氧化氢的界面反应机理和表面活性氧种生成规律，揭示芬顿催化反应体系中，催化剂界面电子迁移循环与污染物降解规律。针对不同水质特征，优化反应工艺，试制芬顿催化反应器，发展多相芬顿催化水处理技术。

针对我国水源水中普遍存在的有机微污染问题，本项目提出制备过渡金属和稀土金属掺杂的类钙钛矿型复合氧化物催化剂，可以高效催化氧化水中典型的难降解有机污染物如医药品、农药等。因此，我们通过溶胶-凝胶法制备了LaFeO3和LaMnO3钙钛矿、铜掺杂Bi2O3/Bi0以及水热法制备了铜掺杂MCM-41分子筛等纳米类芬顿反应催化剂。通过一系列结构表征和性能评价，证实上述材料能够有效催化过氧化氢去除水中的抗生素和农药类有机化合物，进一步研究了过氧化氢与催化剂在固液界面的相互作用过程、催化剂催化分解过氧化氢的界面反应机理和表面活性氧种生成规律，揭示了芬顿催化反应体系中，催化剂界面电子迁移循环与污染物降解的规律，明确了过氧化氢在芬顿催化反应过程中所扮演的角色。通过XRD、XPS、ATR-FTIR、ESR等技术，从过氧化氢的表面络合分解、利用效率、晶格态金属价态的相互转换、以及活性自由基的生成情况等方面提出了相应的多相芬顿催化反应机制。相关研究结果目前已经发表SCI论文10篇。进一步优化反应条件，确定有机污染物芬顿催化降解的最佳反应工艺参数，以铜基复合氧化铝小球为催化剂搭建了多相芬顿固定床反应器，无需外能辅助（如紫外、超声和微波等）在常温常压条件下即可高效去除医药品苯妥英，很有希望用于实际水体处理，为促进多相芬顿催化氧化技术的实用化提供科学依据和技术支撑。