【作者】 王宏奎；

【导师】 赵继华；

【作者基本信息】 兰州大学 ， 物理化学， 2011， 硕士

【摘要】 随着工业技术的不断提高,载体的性能对于整个催化剂的影响越来越受到人们的关注。因此制备具有特殊形貌、分散均匀、粒径小和适当孔分布等特点的γ-Al2O3材料对于工业生产具有重要意义,而负载IB族金属纳米复合催化剂的制备更成为世界科学研究的热点之一。本论文采用胶束溶液法在阴离子表面活性剂双2-乙基己基琥珀酸酯磺酸钠(AOT)体系中制备了直径小于5nm、比表面积为327.6m2/g的拟薄水铝石。分别用层状液晶模版法和微乳液法得到了六角环状氧化铝前躯体和直径小于10nm的纤维状氧化铝材料。同时研究了用微乳液法制备以γ-Al2O3为载体负载Ag、Cu纳米金属颗粒的复合双金属催化剂：发现在立体网状结构的γ-Al2O3载体上能够得到均匀分散的复合双金属催化剂,并对负载不同Ag、Cu摩尔比的系列材料进行表征。XPS分析显示催化剂中的Ag、Cu存在强烈的相互作用,这种相互作用使Ag和Cu更容易失去电子。以苯乙烯环氧化反应评价催化剂的性能,结果表明在Ag/Cu摩尔比为3/1时,环氧苯乙烷的选择性最高,达到76.6%；在Ag/Cu摩尔比为1/1时,苯乙烯的转化率最大,达到94.6%。推测反应的机理可能是：Ag吸附O2-,Cu提供更多的活性位吸附苯乙烯分子,Ag与Cu之间强烈的相互作用使O2-在二者表面传递,因此O2更加容易与苯乙烯反应。更多还原

【Abstract】 As the improvement of industrial technology, the support quality is growing important for the performance of catalyst. Therefore, it is very important to prepare evenly dispersedγ-Al2O3 nanomaterial with special morphologies, small and appropriate pore size distribution through different methods in industry. In recent years, the preparation of nano-load IB group metal composite catalysts supported onγ-Al2O3 has attracted a great deal of attention from scientists.Herein, we prepared nanofibers (<5nm) of pseudo-boehmite (PB) with a high surface area (327.6m2/g) using AOT micelle solution template method. A hexagonal ring precursor of alumina and nanofibers ofγ-Al2O3 (the diameter is less than 10nm) were prepared by lamellar liquid crystal method and microemulsion template method respectively.Then, we selected microemulsion template method to prepare Ag-Cu/γ-Al2O3 complex catalysts. A series of Ag/Cu bimetallic nanoparticles at various molar ratios in reticulate-like y-Alumina were synthesized. XPS analysis showed that there was a strong interaction between Ag and Cu that made both Ag and Cu more likely to lose electrons. The catalytic performances of catalysts were tested by styrene epoxidation. The results showed that the styrene oxide selectivity could reach 76.6% at Ag/Cu molar ratio of 3/1, while the maximum conversion (up to 94.6%) appeared at Ag/Cu molar ratio of 1/1. The possible mechanism of the reaction:the O2- adsorbed on the silver surface can migrate to the copper surface and react with the adsorbed styrene easily.更多还原