Effect of reduction temperature on selective hydrogenation of crotonaldehyde over Ir/TiO2 catalysts
Effect of reduction temperature on selective hydrogenation of crotonaldehyde over Ir/TiO2 catalysts
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DOI：
10.1016/j.apcata.2012.05.024
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发表时间：
2012-08
影响因子：
5.5
通讯作者：
Ping Chen;Jiqing Lu;Guanqun Xie;Gengshen Hu;Lin Zhu;Liangfeng Luo;Weixin Huang;M. Luo
中科院分区：
文献类型：
--
作者：
Ping Chen;Jiqing Lu;Guanqun Xie;Gengshen Hu;Lin Zhu;Liangfeng Luo;Weixin Huang;M. Luo
在 Ir/TiO2 催化剂上进行巴豆醛的气相选择性加氢，研究还原温度对其催化行为的影响。 100℃还原的催化剂含有大量的强路易斯酸位点，由于巴豆醛分子在活性位点上的强烈吸附，不利于活性。此外，由于CC键和缺电荷的Ir物种之间的相互作用，对巴豆醇的选择性被抑制，这有利于丁醛的形成。当催化剂在高温下还原时，发现由于CO键和Ir物种之间的适度相互作用以及减弱的表面路易斯酸位点，300°C适合高活性和选择性。然而，较高的还原温度（500°C）导致羰基碳与富含电荷的Ir物质牢固结合并抑制活性，这可能与强金属-载体相互作用（SMSI）有关。
Vapor-phase selective hydrogenation of crotonaldehyde was conducted over Ir/TiO2catalysts to investigate the effect of reduction temperature on the catalytic behaviors. The catalyst reduced at 100°C contained large amount of strong Lewis acid sites, which was detrimental to the activity because of the strong adsorption of crotonaldehyde molecules on the active sites. Also, the selectivity to crotyl alcohol was suppressed due to the interaction between CC bond and the charge-deficient Ir species, which favored the formation of butanal. When the catalyst was reduced at high temperature, it was found that 300°C was appropriate for high activity and selectivity, due to the moderate interaction between the CO bond and the Ir species, as well as the weakened surface Lewis acid sites. However, higher reduction temperature (500°C) led to a strong bonding of carbonyl carbon and the charge-rich Ir species and suppresses the activity, which may be related to a strong metal–support interaction (SMSI).