Au-Pd supported nanocrystals prepared by a sol immobilisation technique as catalysts for selective chemical synthesis
Au-Pd supported nanocrystals prepared by a sol immobilisation technique as catalysts for selective chemical synthesis
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DOI：
10.1039/b719345a
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发表时间：
2008-01-01
影响因子：
3.3
通讯作者：
Hutchings, Graham J.
中科院分区：
文献类型：
--
作者：
Lopez-Sanchez, Jose Antonio;Dimitratos, Nikolaos;Hutchings, Graham J.
近年来，金和金钯纳米颗粒的催化作用引起了人们的广泛关注。这些纳米晶材料已被发现对选择性氧化和全氧化非常有效，但在大多数情况下，催化剂是通过沉淀或浸渍制备的。我们报道了通过溶胶固定化技术制备的碳负载的Au-Pd纳米晶催化剂，并将其与浸渍法制备的Au-Pd催化剂进行了比较。对催化剂在苯甲醇氧化和过氧化氢直接合成两种选择性化学合成中的应用进行了评价。使用扫描透射电子显微镜和x射线光电子能谱对催化剂进行了结构表征。与浸渍法制备的催化剂相比，溶胶固定化法制备的催化剂具有更高的过氧化氢合成、加氢和甲醇氧化活性。该方法有利于使用低得多的金属浓度，这是催化剂设计的一个关键特征，特别是对于过氧化氢的合成。
Catalysis by gold and gold-palladium nanoparticles has attracted significant research attention in recent years. These nanocrystalline materials have been found to be highly effective for selective and total oxidation, but in most cases the catalysts are prepared using precipitation or impregnation. We report the preparation of Au-Pd nanocrystalline catalysts supported on carbon prepared via a sol-immobilisation technique and these have been compared with Au-Pd catalysts prepared via impregnation. The catalysts have been evaluated for two selective chemical syntheses, namely, oxidation of benzyl alcohol and the direct synthesis of hydrogen peroxide. The catalysts have been structurally characterised using a combination of scanning transmission electron microscopy and X-ray photoelectron spectroscopy. The catalysts prepared using the sol immobilisation technique show higher activity when compared with catalysts prepared by impregnation as they are more active for both hydrogen peroxide synthesis and hydrogenation, and also for benzyl alcohol oxidation. The method facilitates the use of much lower metal concentrations which is a key feature in catalyst design, particularly for the synthesis of hydrogen peroxide.