Mesoporous carbon-confined Au catalysts with superior activity for selective oxidation of glucose to gluconic acid
Mesoporous carbon-confined Au catalysts with superior activity for selective oxidation of glucose to gluconic acid
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DOI：
10.1039/c3gc36891b
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发表时间：
2013-03
期刊：
影响因子：
9.8
通讯作者：
Chun-yan Ma;Wenjuan Xue;Jinjun Li;W. Xing;Z. Hao
中科院分区：
文献类型：
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作者：
Chun-yan Ma;Wenjuan Xue;Jinjun Li;W. Xing;Z. Hao
通过纳米复制和胶体金沉积方法成功制备了一系列有序介孔碳（OMC）负载的金催化剂。结构分析表明，通过调整用于制备碳载体的硼酸用量，可以在3.2-7.6 nm范围内可控地调节催化剂的介孔尺寸。 TEM 观察表明，Au 纳米颗粒均匀分散在碳载体的中孔通道中。这些 Au/OMC 催化剂在 40 °C、pH 9 下进行了葡萄糖有氧氧化生成葡萄糖酸的测试。结构分析和反应结果表明，这些催化剂的活性与其介孔尺寸密切相关。与其他研究人员之前报道的催化剂相比，介孔尺寸为5.4 nm的催化剂表现出优异的催化活性，TOF为4.308 molglucose molAu−1 s−1。这种高活性主要归因于其独特的结构，由与 3.3 nm Au 纳米颗粒结合的 5.4 nm 介孔通道组成，有利于葡萄糖分子和 Au 纳米颗粒之间的接触。此外，该催化剂表面存在的丰富的活性氧也促进葡萄糖氧化。
A series of ordered mesoporous carbon (OMC)-supported Au catalysts were successfully prepared by nano-replication, followed by colloidal gold deposition method. Structural analysis showed that the mesopore sizes of the catalysts can be tuned controllably in the range of 3.2–7.6 nm by adjusting the dosage of boric acid used to prepare the carbon supports. TEM observations revealed that the Au nanoparticles were dispersed uniformly in the mesopore channels of the carbon supports. These Au/OMC catalysts were tested for the aerobic oxidation of glucose to produce gluconic acid at 40 °C and pH 9. As demonstrated by the structural analysis and reaction results, the activities of these catalysts were closely related to their mesopore sizes. The catalyst with a mesopore size of 5.4 nm exhibited a superior catalytic activity with a TOF of 4.308 molglucose molAu−1 s−1 to the catalysts reported previously by other researchers. This high activity was mainly ascribed to its unique structure, consisting of 5.4 nm mesopore channels incorporated with 3.3 nm Au nanoparticles, which facilitates contact between glucose molecules and Au nanoparticles. Besides, the abundant active oxygen species existing on this catalyst surface also promote glucose oxidation.