Structure–property relationships of copper modified mesoporous TiO2 materials on alkyne homocoupling reactions
Structure–property relationships of copper modified mesoporous TiO2 materials on alkyne homocoupling reactions
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DOI：
10.1016/j.jcat.2016.03.009
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发表时间：
2016-06
影响因子：
7.3
通讯作者：
Zhu Luo;Shaylin A. Cetegen;Ran Miao;T. Jiang;Sheng-Yu Chen;T. Jafari;Yashan Zhang;S. Suib
中科院分区：
文献类型：
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作者：
Zhu Luo;Shaylin A. Cetegen;Ran Miao;T. Jiang;Sheng-Yu Chen;T. Jafari;Yashan Zhang;S. Suib
采用掺杂、无溶剂和浸渍三种不同的改性方法，制备了一系列铜负载量（0- 15mol%）的介孔Cu-TiO 2材料。采用PXRD、N2吸附、SEM、EDX元素分布和XPS等技术对改性过程对改性前后的物化性能进行了表征。在TiO 2晶格中检测到Cu+（通过掺杂方法）或在TiO 2表面上检测到CuO（通过无溶剂和浸渍方法）。通过Cu的改性，介孔Cu-TiO 2材料的比表面积可提高到128 m2/g。以空气为唯一氧化剂，在温和的反应条件下，不添加任何添加剂，考察了Cu-TiO 2材料对炔-炔均偶联反应的催化活性。掺杂后的Cu-TiO 2材料表现出最高的催化活性（1，4-二苯基-1，3-丁二炔产率> 99%）。讨论了不同催化剂的催化机理、活性中心和结构与性能的关系。影响Cu-TiO 2材料催化性能的主要因素是Cu的负载量、负载状态、比表面积和孔径分布。在收集的样品上进行了可重复使用性测试，没有洗涤，即使在三个循环后也达到了74%的产率。
Three different modification (doping, solvent free, and impregnation) methods were used to obtain a series of mesoporous Cu–TiO2materials with various copper loading amounts (0–15 mol%). The influence of the modification procedure on the physico-chemical properties was characterized by PXRD, N2sorption, SEM, EDX elemental mapping, and XPS techniques. The presence of copper species has been detected either in the TiO2lattice as Cu+(via doping methods) or on the surface of TiO2as CuO species (via solvent free and impregnation methods). With the modification of Cu, the surface area of mesoporous Cu–TiO2materials can be increased up to 128 m2/g. The catalytic activities of Cu–TiO2materials were investigated using the alkyne–alkyne homocoupling reaction with air as the sole oxidant under mild reaction conditions without any additives. The doped Cu–TiO2materials show the highest catalytic activity (1,4-diphenyl-1,3-butadiyne yields > 99%). The different catalytic mechanisms, active sites, and structure–property relationships of all the catalysts are discussed. Definitive features affecting the catalytic performance of the obtained Cu–TiO2materials are the loading amounts and the states of Cu, surface area, and pore size distributions. Reusability tests were conducted on the collected sample without washing, and 74% yield was achieved even after three cycles.