Galvanic Deposition of Au on Paperlike Cu Fiber for High-Efficiency, Low-Temperature Gas-Phase Oxidation of Alcohols
Galvanic Deposition of Au on Paperlike Cu Fiber for High-Efficiency, Low-Temperature Gas-Phase Oxidation of Alcohols
复制标题
纸状铜纤维上电沉积金用于醇的高效低温气相氧化
DOI：
10.1002/cctc.201100138
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发表时间：
2011-10-01
期刊：
影响因子：
4.5
通讯作者：
Lu, Yong
中科院分区：
文献类型：
--
作者：
Zhao, Guofeng;Hu, Huanyun;Lu, Yong
成功制备了高活性、高选择性、高导热性的铜载金纤维催化剂，用于各种醇的高效气相选择氧化。通过将Au电沉积到由5体积% Cu纤维（8 μ m直径）和95体积%空隙率组成的薄片微纤维结构上获得Au/Cu纤维催化剂。最好的催化剂是Au-3/Cu-fiber-200（Au负载量：3 wt%;在空气中于200 ℃下煅烧），其使用20 h（-1）的高重时空速对无环、苄基和多元醇有效。在220 ℃下获得86%的苯甲醇转化率和99%的苯甲醛选择性。在250 ℃下，环丙烷甲醇可转化为环丙烷甲醛，转化率为91%，选择性为95%。在340 ℃下，1，2-丙烷的转化率高达92%，选择性中等，为74%。挥发性不饱和醇如巴豆醇和3-甲基-2-丁烯醇的氧化也可以在280 ℃下以良好的转化率高选择性地进行。在苯甲醇的选择性氧化反应中，由于传热能力的增强，允许大量反应热的快速耗散，在催化剂床和反应器外壁之间观察到小于10 ℃的低Δ T。反应过程中形成了特殊的AuCu（合金）-Cu 2 O活性复合物，它们的协同作用有助于提高低温活性。从性质上讲，AuCu合金可以催化Cu 2 O-H物种与O-2的氧化，释放活性Cu 2 O位。
The highly active and selective gold-on-copper fiber catalysts with excellent heat conductivity were successfully prepared for high-efficiency gas-phase selective oxidation of various alcohols. The Au/Cu-fiber catalysts were obtained by conducting galvanic deposition of Au onto a thin-sheet microfibrous structure that consisted of 5 vol% Cu-fiber (8 mu m diameter), and 95 vol% voidage. The best catalyst was Au-3/Cu-fiber-200 (Au loading: 3 wt%; calcined at 200 degrees C in air), which was effective for acyclic, benzylic, and polynary alcohols using a high weight hourly space velocity of 20 h(-1). Benzyl alcohol conversion of 86% was obtained with 99% selectivity to benzaldehyde at 220 degrees C. Cyclopropanemethanol could be transformed to cyclo-propanecarboxaldehyde, with conversion of 91% and selectivity of 95% at 250 degrees C. 1,2-Propanediol demonstrated a high con-version of 92%, with a medium selectivity of 74% at 340 degrees C. An oxidation of volatile unsaturated alcohols, such as crotyl alcohol and 3-methyl-2-butenol, could also proceed highly selectively with good conversions at 280 degrees C. A low Delta T of less than 10 degrees C between the catalyst bed and the external wall of the reactor was observed in the selective oxidation of benzyl alcohol owing to the enhanced heat-transfer ability that permits rapid dissipation of large quantities of the reaction heat. Special AuCu(alloy)-Cu2O active composites were formed during the reaction, and their cooperative effect contributed to increasing the low-temperature activity. By nature, the AuCu alloy can catalyze the oxidation of Cu2O-H species with O-2 to release active Cu2O sites.