Solvent-free aerobic oxidation of alcohols using supported gold palladium nanoalloys prepared by a modified impregnation method
Solvent-free aerobic oxidation of alcohols using supported gold palladium nanoalloys prepared by a modified impregnation method
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DOI：
10.1039/c4cy00387j
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发表时间：
2014-01-01
影响因子：
5
通讯作者：
Hutchings, Graham J.
中科院分区：
文献类型：
--
作者：
Morad, Moataz;Sankar, Meenakshisundaram;Hutchings, Graham J.
合成具有可控尺寸、形态和组成的稳定、负载型双金属纳米合金具有重要的实际意义。与它们的单核苷酸类似物相比，这些材料在功能性质上表现出显着的增强，可以在包括催化在内的各个领域中开发。最近，我们报道了一种简单的过量阴离子改性的浸渍法制备负载型金-钯催化剂，它提供了很好的控制的颗粒大小和组成，而不使用任何稳定剂配体的制备。在这里，我们报告的结果，从比较研究中使用这种改性浸渍催化剂的无溶剂的有氧氧化醇在两个不同的反应器：玻璃搅拌反应器和微填充床反应器下分批和连续模式分别。这些改性的浸渍催化剂是特别有活性的，更重要的是，当在流动条件下在微填充床反应器中测试时，观察到稳定数天而没有任何失活迹象，这与在稳定剂配体存在下通过溶胶固定化方法制备的相同催化剂形成对比，所述相同催化剂显示在10-12小时内转化率降低3-5%。
The synthesis of stable, supported, bimetallic nanoalloys with controlled size, morphology and composition is of great practical importance. Compared to their monometallic analogues, such materials exhibit remarkable enhancement in functional properties, which can be exploited in various fields including catalysis. Recently, we have reported a simple excess anion modification of the impregnation method to prepare supported gold-palladium catalysts which gives very good control over the particle sizes and the composition without using any stabilizer ligands in the preparation. Here, we report the results from a comparative study of using this modified impregnation catalyst for the solvent-free aerobic oxidation of alcohols in two different reactors: a glass stirred reactor and a micro packed bed reactor under batch and continuous mode respectively. These modified impregnation catalysts are exceptionally active and more importantly, when tested in a micro packed bed reactor under flow conditions, are observed to be stable for several days without any sign of deactivation in contrast to the same catalyst prepared by the sol immobilization method in the presence of stabilizer ligands which showed a 3-5% decrease in conversion over 10-12 h.