Influence of compressed carbon dioxide on hydrogenation reactions in cyclohexane with a Pd/C catalyst
Influence of compressed carbon dioxide on hydrogenation reactions in cyclohexane with a Pd/C catalyst
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DOI：
10.1021/ie071453g
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发表时间：
2008-08
影响因子：
4.2
通讯作者：
J. Hao;Chunyu Xi;Haiyang Cheng;Ruixia Liu;Shuxia Cai;M. Arai;F. Zhao
中科院分区：
文献类型：
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作者：
J. Hao;Chunyu Xi;Haiyang Cheng;Ruixia Liu;Shuxia Cai;M. Arai;F. Zhao
本文以环己烷为溶剂，Pd/C为多相催化剂，考察了CO2膨胀液体介质对苯乙烯、柠檬醛和硝基苯与氢加氢反应的催化性能。在CO2膨胀的环己烷相中，加氢反应速度加快，产物选择性改变。在柠檬醛加氢反应中，香茅醛的选择性随CO_2压力的增加而降低，在纯环己烷中，选择性由∼的80%下降到16 Mpa时的∼65%。溶解在环己烷相中的CO2可能会加速香茅醛的进一步加氢反应。在硝基苯加氢反应中，在没有密相CO2的情况下，苯胺的选择性很高，达90%，而在液体反应相加压CO2时，选择性可达95%。
The potential of CO2-expanded liquid media for chemical reactions has been examined in this work, using cyclohexane as a solvent and Pd/C as a heterogeneous catalyst for hydrogenation of styrene, citral, and nitrobenzene with H2. The rate of hydrogenation reactions is increased, and the product selectivity is altered in the CO2-expanded cyclohexane phase. In the hydrogenation of citral, the selectivity to citronellal decreases with CO2 pressure, which changes from ∼80% in the neat cyclohexane to ∼65% at 16 MPa. The CO2 dissolved in the cyclohexane phase may accelerate the rate of further hydrogenation of citronellal. In the hydrogenation of nitrobenzene, the selectivity to aniline is large >90% in the absence of dense phase CO2 but it increases up to >95% on CO2 pressurization of the liquid reaction phase.