铁基类芬顿催化剂的构建及非自由基路径去除有机污染物

CONSTRUCTION OF IRON-BASED FENTON-LIKE CATALYSTS FOR ORANIC POLLUTANT REMOVAL VIA NON-RADICAL PATHWAYS

黄世欣

11930309

硕士

材料工程

张作泰

2021-05-23

2021-06-04

南方科技大学

深圳

基于类芬顿试剂的高级氧化过程（AOPs）是现在发展相对成熟的污水处理技术。在催化剂、光、热、电等条件下，类芬顿试剂将激发生成·OH等活性氧物种，从而促进有机污染物降解，并可以显着降低水环境中的化学需氧量和总有机碳。然而，开发高效率、高稳定性的催化剂，并应用于大规模工业生产仍然是类芬顿氧化技术研究的长期目标。传统的Fe2+-H2O2芬顿试剂具有高效的催化性能，但在实际的工业应用中难以回收催化剂，金属残留严重，容易产生二次污染。最近，碳纳米管、氧化石墨烯、活性炭等碳材料因其高比表面积、高导电性、良好的生物相容性等优点，被广泛用作AOPs催化剂。但单纯的碳材料活性位点少、反应活性有待提高。过渡金属掺杂的碳材料可以有效减少金属流失，避免金属活性组分聚集，促进反应过程中的物质传输。基于以上研究背景，本论文构建了两种过渡金属掺杂的碳材料，包括铁、氮共掺杂碳材料（Fe@NC）和硫掺杂铁-氮-碳材料（Fe@SNC），并将其在AOPs中应用。本论文主要研究内容如下：采用现代化分析技术研究了Fe@NC表面形貌、元素组成、比表面积等理化性质，考察了Fe@NC活化高碘酸盐（PI）降解含氯污染物对氯苯酚（4-CP）的性能，分析了对氯苯酚降解过程的影响因素（pH、反应温度、阴离子影响等）和催化剂的循环稳定性。自由基淬灭实验表明，Fe@NC活化高碘酸盐过程中未产生活性自由基，该过程主要通过非自由基途径进行。系统地比较了Fe@SNC催化剂在活化过一硫酸盐（PMS）和PI两种氧化剂降解罗丹明B的催化活性、反应机理、影响因素和稳定性能，分析了两种体系各自的优势和特点。研究表明，PMS体系反应更加迅速，但伴随着高浓度的铁离子浸出；PI体系反应温和，但铁离子的浸出浓度较低。通过对降解机理分析，PMS体系中高价铁为主要的活性物种，而PI体系则是基于电子转移的非自由基途径。

Advanced oxidation processes (AOPs) based on Fenton-like reagents are currently mature wastewater treatment methods. Under conditions of catalyst, light, heat, electricity, etc., Fenton-like reagent will generate reactive oxygen species such as ·OH, thereby promoting the degradation of organic pollutants, and significantly reducing the chemical oxygen demand (COD) and total organic carbon (TOC). Recently, carbon materials have been widely used as catalysts in AOPs due to their high specific surface area, high conductivity, and high biocompatibility. However, limited active sites and low reactivity restriant its practical application. Transition metal-doped carbon materials are able to reduce metal leaching, prevent metal aggregation, and further expose metal active sites.In this thesis, an iron and nitrogen codoped carbon material (Fe@NC) and sulfur-doped nitrogen-iron-carbon catalyst (Fe@SNC) are constructed. The research content is mainly divided into the two parts: Fe@NC is used as periodate (PI) activator to degrade 4-chlorophenol (4-CP), and the influential factors (such as pH, reaction temperature, inorganic anion, etc.) and the activator stability are analyzed. Reactive oxygen species are not detected during radical quenching tests in the process of periodate activation by Fe@NC, and thus the process is more likely to be a non-radical pathway.The catalytic activity, reaction mechanism, influencing factors and stability performance of Fe@SNC in activating peroxymoosulfate (PMS)/PI to degrade RhB were systematically compared, and the respective advantages and characteristics of the two systems were analyzed. It is found that PMS-based system reacts more rapidly with RhB than the PI-based system, but with much higher iron dissolution concentration. In terms of reaction mechanism, PMS-based system degraded RhB by high-valent iron-oxo species, while the PI-based system degraded RhB via a non-radical electron-transfer regime.

铁基催化剂 高级氧化技术 高碘酸钠 过硫酸氢钾 非自由基途径

Iron-based catalyst advanced oxidation process sodium periodate potassium monopersulfate non-radical pathway

中文

独立培养

南方科技大学

黄世欣. 铁基类芬顿催化剂的构建及非自由基路径去除有机污染物[D]. 深圳. 南方科技大学,2021.