宽pH响应铜铁矿基高效多相芬顿催化剂的设计构筑及界面作用机制研究

At present, how to design and synthesize a heterogeneous Fenton catalyst with a wide working pH range and improve its H2O2 utilization efficiency in ·OH formation are the key issues to be solved in the development of Fenton technology. This project proposed to develop a series of CuFeO2 based heterogeneous Fenton catalysts with different micro-structures and surface properties via optimizing preparation condition, in-situ doping element and atomic ratios. The effects of oxygen vacancy and surface acid-base property et al. on the heterogeneous Fenton performance of CuFeO2 were investigated by the degradation efficiency of sulfamethoxazole and estradiol. Furthermore, the interfacial reaction process of H2O2 and CuFeO2 and H2O2 activation mechanism were revealed by in-situ online spectroscopy methods such as attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), surface enhanced resonance Raman scattering (SERS) and DFT theoretical calculation. After comprehensive analysis, the key parameters that determine H2O2 conversion into ·OH over CuFeO2 at a wide pH range could be found out, which will provide theoretical foundation for the design of highly efficient Fenton catalysts with a wide working pH range. Finally, a heterogeneous Fenton fixed-bed system will be designed and the operation conditions will be optimized, in which the typical antibiotics and endocrine disruptors in water can be efficiently degraded with safe transformation. Hence, the findings in this study can accelerate the application of heterogeneous Fenton oxidation in practical water treatment.

如何设计构筑具有宽pH响应的高效多相芬顿催化剂，提高H2O2分解产生·OH的效率，始终是芬顿技术发展需要解决的关键科学问题。本项目提出以铜铁矿为基础，通过优化合成条件、原位掺杂元素及比例构成等调控其微观结构和表面特性，结合水中磺胺甲恶唑和雌二醇的降解效率，研究氧空位与表面酸碱性等因素对铜铁矿多相芬顿催化性能的影响规律；利用衰减全反射红外和表面增强共振激光拉曼等原位光谱表征手段以及DFT理论计算，揭示铜铁矿活性位点与H2O2的界面作用过程和机理；经过综合分析，找出影响铜铁矿在宽pH范围高效催化H2O2产生·OH的关键因素，为研制宽pH响应的高效多相芬顿催化剂提供依据。最后，通过设计动态反应器与优化运行条件，实现水中典型抗生素和内分泌干扰物的高效去除与安全转化，有效推动多相芬顿催化氧化技术的实用化进程。

针对异相芬顿技术在实际应用过程中存在有效pH范围窄、H2O2分解产生•OH效率低的问题，本项目以CuFeO2为基础，通过优化合成条件、原位掺杂元素及比例构成等调控其微观结构和表面特性，以达到拓宽芬顿反应pH范围、强化H2O2定向转化为•OH的目的。首先，基于反应条件优化、元素组成调控等成功制备了系列CuFeO2、CCN/CuFeO2、MgO/CuFeO2、SC@CuFeO2等多种异相芬顿催化剂，考察了上述催化剂在酸性至碱性条件下对水体中抗生素如氧氟沙星(OFX)和盐酸四环素(TC)、磺胺甲恶唑（SMX）去除效能；基于同步辐射技术（EXAFS）、DFT理论计算和相关探针实验等表征结果，阐明了铜铁矿活性位点与H2O2的界面作用过程（吸附/络合/分解）和机理；揭示了催化剂晶面暴露、表面酸碱性调控是影响铜铁矿在宽pH范围高效催化H2O2产生•OH的关键因素，而活性氧物种由短半衰期的•OH到长半衰期1O2的转变也是催化剂在碱性pH条件下实现污染物高效去除的根本原因。通过分析催化反应过程中可能产生的中间产物，提出了抗生素类污染物在催化反应过程中的安全降解路径。本项目的研究为研制宽pH响应的高效多相芬顿催化剂提供依据，可有效推动多相芬顿催化氧化技术的实用化进程。相关研究结果已经发表SCI文章38篇，较好地完成了项目最初的研究目标与考核指标。