A multiphase reaction medium including pressurized carbon dioxide and water for selective hydrogenation of benzonitrile with a Pd/Al2O3 catalyst
A multiphase reaction medium including pressurized carbon dioxide and water for selective hydrogenation of benzonitrile with a Pd/Al2O3 catalyst
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DOI：
10.1016/j.apcata.2013.03.004
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发表时间：
2013-04
影响因子：
5.5
通讯作者：
H. Yoshida;Yu Wang;S. Narisawa;S. Fujita;Ruixia Liu;M. Arai
中科院分区：
文献类型：
--
作者：
H. Yoshida;Yu Wang;S. Narisawa;S. Fujita;Ruixia Liu;M. Arai
研究了在加压CO2和水存在下，Pd/Al 2 O3催化剂上苯甲腈的加氢反应。该多相反应体系可有效地选择性制备所需的苄胺伯胺，且催化剂不会失活。伯胺转移到水相中，阻止了伯胺与亚胺中间体在有机相中（苯甲腈）反应生成仲胺，从而提高了伯胺的选择性。此外，CO2分子与伯胺的相互作用也可以提高伯胺的选择性。在不存在水的情况下，催化剂由于氨基甲酸盐在催化剂表面上的积累而失活。但由于盐溶于水，不会存款在水相和有机相界面层的催化剂上，因此加入水可避免这种失活。
The hydrogenation of benzonitrile was studied with a Pd/Al2O3catalyst in the presence of pressurized CO2and water. This multiphase reaction system was effective for the selective production of the desired primary amine of benzylamine with no deactivation of the catalyst. The enhanced selectivity to the primary amine resulted from its transfer into water phase, which prevented the primary amine from reacting with an intermediate of imine into the secondary amine in the organic phase (benzonitrile). In addition, interactions of CO2molecules with the primary amine could also increase its selectivity. In the absence of water, the catalyst was deactivated by the accumulation of a carbamate salt on the surface of catalyst. But this deactivation was avoided by the addition of water because the salt was soluble in water and it did not deposit on the catalyst existing at interfacial layer between the water and organic phases.