Selective hydrogenation of crotonaldehyde on Au/HSA-CeO2 catalysts
Selective hydrogenation of crotonaldehyde on Au/HSA-CeO2 catalysts
复制标题
DOI：
10.1016/j.jcat.2006.05.031
复制
发表时间：
2006-08
影响因子：
7.3
通讯作者：
B. Campo;M. Volpe;S. Ivanova;R. Touroude
中科院分区：
文献类型：
--
作者：
B. Campo;M. Volpe;S. Ivanova;R. Touroude
巴豆醛的气相氢化反应在高表面积CeO 2负载的Au上进行，该催化剂预先在120 °C下还原。在初始非平衡阶段分析的产物显示形成了大量的乙醇，其随着运行时间的推移而迅速减少，并在平衡条件下被缩合产物（主要是2，4，6-辛三烯醛）的组合所取代。巴豆醇的产量在任何时候都大大超过丁醛的产量。在稳态条件下，巴豆醇与丁醛之比等于1.7。当催化剂在300 °C空气中焙烧时，在还原处理之前，初始阶段的乙醇生成量和稳态下的缩合产物生成量均减少。此外，观察到巴豆醇的产量显着增加，而丁醛的形成不受影响。最后，当巴豆醇/丁醛比为3时，Au/HSA-CeO 2催化剂对CO键的加氢具有很高的选择性。这些结果与Au/TiO 2 [R.扎内拉，C.路易斯，S。戈尔焦河Touroude，J. Catal.223（2004）328]。酸碱位点的作用，以及HSA-CeO 2的氧化还原中心，进行评估。尽管氧化铈参与了反应，但Au/HSA-CeO 2的催化性能主要归功于金纳米颗粒。
The gas-phase hydrogenation of crotonaldehyde was carried out over Au supported on high-surface area (HSA) CeO2, previously reduced at 120 °C. The products analyzed during the initial, nonequilibrium stage showed the formation of large amounts of ethanol, which rapidly decreased with time on stream and were replaced by a combination of condensation products (mainly 2,4,6-octatrienal) under equilibrium conditions. The production of crotyl alcohol largely exceeded that of butanal at any time on stream. Under steady-state conditions, the crotyl alcohol-to-butanal ratio was equal to 1.7. When the catalyst was recalcined in air at 300 °C, just before the reduction treatment, the formation of ethanol in the initial stage and that of condensation products under steady state decreased. Besides, notable increase in the production of crotyl alcohol was observed, whereas butanal formation was unaffected. Finally, Au/HSA-CeO2is a highly selective catalyst for CO bond hydrogenation when crotyl alcohol/butanal ratio is equal to 3 under a steady-state regime. These results were compared to those obtained for Au/TiO2[R. Zanella, C. Louis, S. Gorgio, R. Touroude, J. Catal. 223 (2004) 328]. The role of acid–base sites, as well as that of the redox centers of HSA-CeO2, is evaluated. Even though ceria sites are engaged in the reaction, the catalytic properties of Au/HSA-CeO2are attributed mainly to the gold nanoparticles.