多价态金属复合氧化物类芬顿催化剂的研制及其去除污染物机制
文献类型：学位论文
| 作者 | 张丽丽 |
| 学位类别 | 博士 |
| 答辩日期 | 2013-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 胡春 |
| 关键词 | 多相芬顿催化剂 多价态金属 高活性 高稳定性 有机污染物去除 Heterogenerous Fenton catalysts Multi-valent metal High activity Long-time stability Organic pollutants removal |
| 其他题名 | Development of Multivalent Metal Composite Oxides Fenton-like Catalysts and Their Removal Mechanism of Pollutants |
| 学位专业 | 环境科学 |
| 中文摘要 | 本论文以多价态Mn和Cu为着眼点，以加快界面电子转移为切入点，致力于开发无需紫外光等外能辅助、中性温和条件下稳定可循环并且易于实际应用的多相芬顿催化剂。本文还通过各种表征手段揭示了多相芬顿催化剂的催化氧化机制，包括H2O2的分解机制和对水中染料、氯酚类和医药品类等有机污染物的降解机制。此外，将粉末状催化剂负载到球状载体上，设计多相芬顿固定床反应器，更便于将多相芬顿催化氧化技术应用到实际废水处理中。 本论文的主要研究工作和成果如下： （1）成功地研制出纳米层状多价态锰氧化物催化剂，利用Mn的不同价态间易于发生电子转换的特点，催化H2O2分解产生多种活性氧物种（1O2、O2•−和•OH），从而使MB在短时间内脱色。 （2）研制出铜掺杂钛酸镧催化剂，不仅引入Cu+和Cu2+，而且Cu的引入诱发钙钛矿结构中Ti由单一的Ti4+转变为Ti3+与Ti4+共存。该催化剂能够催化少量H2O2分解产生大量•OH，在pH 4 − 9的范围内保持较高的芬顿催化活性。Cu+/2+和Ti3+/4+在催化剂结构中的稳定共存，引发 2类芬顿反应，不同的氧化还原电对加速界面电子转移，相互促进，提高了芬顿反应效率和反应稳定性。 （3）研制出铜掺杂氧化铋催化剂，将Cu+和Cu2+稳定地固定于氧化铋结构中，Cu的引入大大促进H2O2分解产生•OH和O2•−，提高了H2O2的有效利用率。Cu+和Cu2+在氧化铋结构中的共存，加速界面电子转移，使该催化剂对多种有机污染物如氯酚类和医药品类等均能够高效地矿化降解，并且具有良好的反复活性。通过多相芬顿催化机制的研究发现反应循环多次之后Cu+和Cu2+的表面浓度比基本不变，说明Cu在催化剂界面形成自循环体系。 （4）由粉状催化剂发展为负载于氧化铝小球的催化剂，将Cu+和Cu2+稳定地固定于氧化铝小球上，并成功地设计出多相芬顿固定床反应器。连续运行四十多天，对 2-CP的催化去除率保持在 60%左右，并且Cu溶出逐渐减少，十几天后检测不出。此外，该反应器对其 他有机污染物如环丙沙星、布洛芬、苯妥英等均具有较高的催化降解活性。 这些研究结果表明所研制的 Cu+和Cu2+共存的多相芬顿催化剂在中性温和条件下具有较高的催化活性和稳定性，所设计的铜基固定床反应器和所提出的多相芬顿催化氧化过程是一种很有前景的实用技术，有望应用于实际废水处理。 |
| 英文摘要 | The thesis is devoted to develop novel heterogeneous Fenton catalysts with high activity and long-term stability under natural conditions, and accelerate the interfacial electron transfer by the formation of multi-valent Mn and Cu. We also investigated the catalytic oxidation mechanism of heterogenous Fenton catalyst, including the decomposition mechanism of H2O2 and the degradation mechanism of different organic pollutants. Moreover, powdered catalysts were successfully loaded on ball-shaped carriers and heterogenous Fenton reactor was successfully designed to be applied in wastewater treatment. The main research contents and results are shown in the following: (1) Nano-scaled layered multivalent manganese oxides were successfully prepared as heterogeneous Fenton catalysts. The existence of multivalent manganese oxides greatly enhanced the interfacial electron transfer so that H2O2 was decomposed into various active oxygen species (i.e., 1O2, O2•− and •OH), leading to the decolorization of MB in short time. (2) Cu-doped LaTiO3 was successfully synthesized. Both Cu+ and Cu2+ were introduced into the catalyst. The introduction of Cu induced the formation of LaTiO3 perovskite in which titanium existed as Ti3+ and Ti4+. Cu-doped LaTiO3 could effectively convert H2O2 into a large amout of •OH and show high Fenton catalytic activity in the initial pH range of 4-9. The stable coexistence of Cu+/2+ and Ti3+/4+ in the perovskite structure could initiate two kinds of Fenton reactions. The formation of different redox potentials could accelerate the interfacial electron transfer, leading to high Fenton catalytic efficiency and stability. (3) Both Cu+ and Cu2+ were stably fixed in Bi2O3 structure to obtain a novel heterogeneous Fenton catalyst, Cu-doped Bi2O3. The incorporation of Cu strongly favored H2O2 decomposition into •OH and O2•−, and improved the effective availability of H2O2. The stable coexistence of Cu+ and Cu2+ in the Bi2O3 structure could accelerate the interfacial electron transfer so that the catalyst was able to effectively degrade and mineralize various organic pollutants, such as chlorophenols and pharmaceuticals. In addition, Cu-doped Bi2O3 showed excellent repetitive activity. The results of heterogeneous Fenton catalytic mechanismstudies indicated that a self-cycling system of Cu was formed since the surface concentration ratio of Cu+ and Cu2+ kept stable after several reaction cycles. (4) Supported catalysts on alumina balls were developed from powdered catalysts. Both Cu+ and Cu2+ were stably fixed on alumina balls and a heterogeneous Fenton reactor was successfully designed to degrade various organic pollutants. Over forty days of continuous operation, Cu-AlOOH/alumina balls kept high catalytic activity on the degradation of 2-CP, and leaching of Cu gradually reduced and could not be detected after ten days. In addition, the heterogenous Fenton reactor was able to effectively degrade other organic pollutants, such as ciprofloxacin (CIP), ibuprofen (IBU), phenytoin (PHT) and others. These results suggest that the synthesized heterogeneous Fenton-like catalysts with multi-valent Cu have high activity and long-term stability under natural conditions. The designed Cu-based fixed-bed reactor and the proposed heterogeneous Fenton-like catalytic oxidation process is a promising and practical technology to apply in actual wastewater treatment. |
| 公开日期 | 2014-10-24 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/7700]  |
| 专题 | 生态环境研究中心_环境水质学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 张丽丽. 多价态金属复合氧化物类芬顿催化剂的研制及其去除污染物机制[D]. 北京. 中国科学院研究生院. 2013. |
入库方式： OAI收割
来源：生态环境研究中心
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