【作者】 乔启成；

【导师】 赵跃民；

【作者基本信息】 中国矿业大学 ， 环境工程， 2014， 博士

【摘要】 本文以提高填充床电化学反应器电极材料的电催化氧化性能以及稳定性为主要目的，开展了新型钛基PbO2阳极、金属氧化物负载γ-Al2O3粒子电极的制备、改性、表征以及电催化氧化酸性橙II（AOII）性能的研究工作，探讨了AOII的降解途径和电催化氧化机理。主要研究内容和结果如下：（1）采用电沉积法制备了不同F-浓度掺杂的钛基PbO2电极。SEM、XRD测试结果表明，F-的掺杂有利于形成β-PbO2的四方体晶体结构、减小晶体颗粒尺寸，提高电极催化活性和稳定性；极化曲线、强化寿命、荧光光谱、循环伏安曲线、电化学阻抗、AOII降解、紫外光谱扫描等测试结果表明，掺杂量为0.04mol/L时最佳。（2）制备了SnO2-Sb2O5、IrO2-Ta2O5、RuO2-IrO2中间层涂层及相应的Ti/SnO2-Sb2O5/PbO2、Ti/IrO2-Ta2O5/PbO2、Ti/RuO2-IrO2/PbO2电极。SEM、XRD、XPS测试结果表明，中间层表面均被PbO2晶粒覆盖、呈现β-PbO2的四方体晶体结构、Pb均主要以Pb4+价态存在；极化曲线、强化寿命、荧光光谱、循环伏安曲线、电化学阻抗、AOII降解、紫外光谱扫描等测试结果表明，中间层可以提高电极稳定性，但同时结合电催化活性考虑，SnO2-Sb2O5作为中间层更为合适。（3）采用电沉积法制备了Bi、Ce、Co、Nd四种金属元素掺杂的Ti/SnO2-Sb2O5/PbO2电极。SEM、XRD、XPS测试结果表明，Nd掺杂后电极表面晶体颗粒大小及分布均匀、为β-PbO+2的四方体晶体结构、Nd主要以Nd3化学态的氧化物形式存在；极化曲线、强化寿命、荧光光谱、循环伏安曲线、电化学阻抗、AOII降解、紫外光谱扫描等测试结果表明，Nd掺杂制备的电极具有更高的电催化活性和稳定性，掺杂量为50:1时最佳。（4）采用浸渍热分解法制备了Cu、Mn、Pb、Sn等单组分金属氧化物以及Sn-Ce-Sb复合金属氧化物负载的γ-Al2O3粒子电极。SEM、EDS、AOII降解、紫外光谱扫描等测试结果表明，Sn/γ-Al2O3粒子电极对AOII催化活性高、稳定性好；Ce的掺杂有利于提高Sn/γ-Al2O3粒子电极的催化性能和稳定性，测试结果表明表面晶体粒径更加细小而均匀，在基体表面覆盖度更高，负载量更大，Sn/Ce摩尔比为10:1时最佳。（5）以优化制备的新型Nd掺杂Ti/SnO2-Sb2O5/PbO2电极为阳极、Sn-Ce-Sb/γ-Al2O3为粒子电极，构建了填充床电化学反应器。采用紫外扫描、FTIR、GC-MS等测试手段，提出了AOII的电催化氧化降解途径。从阳极催生·OH、粒子电极催生·OH、阳极与粒子电极共同催生·OH三个方面提出了AOII电催化氧化机理。更多还原

【Abstract】 To improve the catalytic activity and stability of anode and particle electrode inthe packed-bed electrode reactor, in present work, the novel PbO2anode and γ-Al2O3particle electrode were prepared, optimized, characterized and applied for theelectro-catalytic oxidation of acid orange II (AOII), and the possible degradationpathways and electro-catalytic oxidation mechanisms of AOII were investigated. Themain research contents and results are summarized as follows:(1) The PbO2electrodes doped with different concentration of fluoride wereprepared by electrodeposition. The results of scanning electron microscopy (SEM)and X-ray diffraction (XRD) show that F-doping on the electrode can form tetragonalcrystal structure of β-PbO2, decrease the crystal size, and improve its catalytic activityand stability. Linear-sweep voltammetry (LSV), accelerated lifetime (ALT),fluorospectrophotometry(FP), cyclic voltammetry (CV), electrochemical impedancespectroscopy(EIS), AOIItreatment and UV-Vis analysis reveals that theoptimumconditionofthe concentrationoffluoride doping on the electrode is0.04mol/L.(2)Three different intermediate layers (SnO2-Sb2O5, IrO2-Ta2O5and RuO2-IrO2)were coated on Ti-substrate, and then PbO2was electrodeposited to prepareTi/SnO2-Sb2O5/PbO2, Ti/IrO2-Ta2O5/PbO2and Ti/RuO2-IrO2/PbO2, respectively.SEM, XRD and X-ray photoelectron spectroscopy (XPS) tests show that theintermediate layers are all covered by β-PbO2with tetragonal crystal structure and themain chemical valence of Pb is4+. LSV, ALT, FP, CV, EIS, AOII treatment and UV-Visanalysis reveal that the presence of intermediate layers can increase the stability ofPbO2electrode, and SnO2-Sb2O5is more suitable to be intermediate layer according tothe higher electro-catalytic activity.(3)Ti/SnO2-Sb2O5/PbO2electrodes doped with different metallic elements,including Bi, Ce, Co and Nd, were prepared by anodic codeposition. SEM, XRD andXPS analysis reveal that the Nd-PbO2electrode is covered by β-PbO2with tetragonalcrystal structure and the main chemical valence of Nd is3+, and doping with Nd canuniform the crystal particle size and distribution. The results of LSV, ALT, FP, CV, EIS,AOII treatment and UV-Vis show that the Nd-PbO2electrode exhibits the bestperformance for electro-catalytic oxidation and stability, the optimum condition of Nddoping on the electrode is at the ratio of50:1.(4) Various catalysts with different active single metallic oxides, i.e. Cu,Mn, Pb, Sn and Sn-Ce-Sb complex metal oxides supported over γ-Al2O3used as particleelectrodes were prepared by the incipient wetness impregnation. SEM,energy-dispersive X-ray spectroscopy (EDS), AOIItreatment and UV-Vis testsshowthatSn/γ-Al2O3has excellent electro-catalytic activity and stability for AOII treatment.Doping with Ce can improve the catalytic activity and stability of Sn/γ-Al2O3. Moreover, the results of tests also reveal that the optimum ratio of Sn to Ce is10:1and theSn-Ce-Sb/γ-Al2O3particle electrode is covered with finer and more crystal particles.(5) AOII was treated by a packed-bed electrode reactor with the novelTi/SnO2-Sb2O5/PbO2electrode doped with Nd as anode and Sn-Ce-Sb/γ-Al2O3asparticle electrode. A possible pathway for AOII degradation was proposed bymonitroring the temporal evolution of intermediates in the solution, with the use ofsome techniques including UV-Vis, FTIR and GC/MS. Meanwhile, the possiblemechanism of electro-catalytic oxidation of AOII has also been proposed. By meansof electro-catalytic oxidation, AOII can be completely degraded by hydroxylradicalswhich are generated on anode, particle electrodes, and by the interaction ofanode and particle electrodes.更多还原