cumgal类水滑石及其为前驱体的复合氧化物催化剂的制备 表征和催化性能研究word格式论文.docxVIP

中 文 摘 要开发并应用具有高活性、高产物选择性的催化剂是催化领域的关 键 问 题 。 本 文 通 过 不 同 制 备 方 法 ， 制 备 了 系 列 具 有 层 状 结 构 的 Cu-Mg-Al 类水滑石，并以其为前驱体制备了 Cu-Mg-Al 复合氧化物 催化剂，比较了类水滑石及其复合氧化物的制备方法、制备条件对催 化剂结构和在偶联反应中催化活性的影响。首先采用水热-尿素水解法制备了系列 Cu2+含量不同的 Cu-Mg-Al 类水滑石，考察了这些催化剂在碘苯与苯酚合成二苯醚反应中的性 能。其次，采用双滴-共沉淀法制备了系列 Cu-Mg-Al 类水滑石，与水 热-尿素水解法进行对比，并考察了制备条件对催化剂晶相及催化性 能的影响。运用氮气物理吸附、X 射线衍射、氢气程序升温还原、红 外光谱、扫描电镜等技术对催化剂进行表征。研究了不同方法制得 Cu2+含量不同的 Cu-Mg-Al 类水滑石催化剂的物理化学性质和对催化 剂性能的影响。结果表明，由双滴-共沉淀法制备、nCu2+/nMg2+=2 的 Cu2Mg1Al1-C 催化剂对碘苯与苯酚偶联合成二苯醚表现出最佳的反应 性能，产物二苯醚收率达到了 99 %以上。进一步以 Cu-Mg-Al 类水滑石为前驱体制备了 Cu-Mg-Al 复合氧 化物催化剂，考察了催化剂在碘苯与咪唑合成 1-苯基咪唑的偶联反应中的催化性能。通过表征，研究了焙烧温度和焙烧时间对催化剂的晶化程度、粒径大小、比表面积、氧化还原性和催化性能的影响。关键词Cu-Mg-Al 类水滑石, 复合氧化物, C-O 偶联反应, C-N 偶联反 应ABSTRACTThe development and application of catalyst with high activity and high selectivity is one of the key problems in catalysis. Cu-Mg-Al hydrotalcite like compounds (HLC) were prepared by different methods. Furthermore, their respective Cu-Mg-Al composite oxides were obtained by calcination of HLC. All these samples are applied to the coupling reaction to evaluate the catalytic activity.Firstly, Cu-Mg-Al hydrotalcite like compounds with different Cu-Mg-Al molar ratios were synthesized by urea hydrolysis- hydrothermal synthetic methods. The catalyst performance for the synthesis of diphenyl ether reaction from iodobenzene and phenol was investigated.Secondly, double drop-coprecipitation method was used to prepare the Cu-Mg-Al hydrotalcite like compounds. The influence of the preparation conditions on the crystal phase of catalyst and the catalytic performance was investigated. The synthesized compounds werecharacterized by X-ray diffraction (XRD) 、 hydrogen temperature-programmed reduction (H2-TPR) 、 infrared spectroscopy (IR) and scanning electron microscopy (SEM). The influences of the preparation methods on physical and chemical properties of Cu-Mg-Al catalysts and its catalytic behavior were studied. The results showed that the catalyst derived from double drop-coprec