Nitrogen and oxygen-doped metal-free carbon catalysts for chemoselective transfer hydrogenation of nitrobenzene, styrene, and 3-nitrostyrene with hydrazine
Nitrogen and oxygen-doped metal-free carbon catalysts for chemoselective transfer hydrogenation of nitrobenzene, styrene, and 3-nitrostyrene with hydrazine
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DOI：
10.1016/j.molcata.2014.06.021
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发表时间：
2014-11-01
影响因子：
--
通讯作者：
Arai, Masahiko
中科院分区：
文献类型：
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作者：
Fujita, Shin-ichiro;Watanabe, Hiroyuki;Arai, Masahiko
采用过氧化氢和氨水对活性炭进行表面改性，使其表面掺杂氧和氮。将表面功能化的活性炭催化剂用于水合肼还原硝基苯、苯乙烯和3-硝基苯乙烯的反应。与母体AC催化剂相比，氧和氮掺杂的催化剂促进了硝基苯和3-硝基苯乙烯的还原。它们对苯乙烯的还原活性较低，但对3-硝基苯乙烯的乙烯基还原活性较高。然而，氮掺杂剂抑制3-乙烯基苯胺的乙烯基的还原。功能化AC催化剂可能通过与由氧和氮杂掺杂剂诱导的极化表面的相互作用促进硝基底物的硝基的吸附和活化。这应该使得可以减少表面上的3-硝基苯乙烯的乙烯基。氮掺杂剂阻碍了3-乙烯基苯胺的乙烯基的还原，因为通过其氨基的吸附在由氮掺杂引起的碱性表面上将变得困难。AC用作电导体，并且其性能应该通过表面官能化来增强，这将有助于在表面上形成还原物质，例如二酰亚胺和来自肼的质子。目前的研究结果表明，氧和/或氮掺杂的，功能化的碳材料可能是有前途的无金属的多任务催化剂。(C)2014爱思唯尔有限公司版权所有。
An activated carbon (AC) was treated by hydrogen peroxide and ammonia to dope oxygen and nitrogen on its surface. The surface-functionalized AC catalysts were used for the transfer reduction of nitrobenzene, styrene, and 3-nitrostyrene by hydrazine hydrate. The reduction of nitrobenzene and 3-nitrostyrene was promoted over the oxygen- and nitrogen-doped catalysts compared to the parent AC catalyst. Those were less active for the reduction of styrene but active for the reduction of vinyl group of 3-nitrostyrene. However, the nitrogen dopant suppressed the reduction of vinyl group of 3-vinylaniline. The functionalized AC catalysts are likely to facilitate the adsorption and activation of nitro group of the nitro substrates through interactions with polarized surface induced by the oxygen and nitrogen hetero dopants. This should make it possible to reduce the vinyl group of 3-nitrostyrene on the surface. The nitrogen dopant hindered the reduction of the vinyl group of 3-vinylaniline because the adsorption through its amino group should become difficult on the surface of basic nature induced by the nitrogen doping. The AC serves as an electrical conductor and its performance should be enhanced by the surface functionalization and this would contribute to the formation of reducing species such as diimide and proton from hydrazine on the surface. The present results show that oxygen- and/or nitrogen-doped, functionalized carbon materials could be promising as metal-free multi-task catalysts. (C) 2014 Elsevier B.V. All rights reserved.