The synergic effects at molecular level in CoS2 for selective hydrogenation of nitroarenes
The synergic effects at molecular level in CoS2 for selective hydrogenation of nitroarenes
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CoS2在分子水平上对硝基芳烃选择性加氢的协同作用
DOI：
10.1039/c7gc03122j
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发表时间：
2018
期刊：
影响因子：
9.8
通讯作者：
Wang Yong
中科院分区：
文献类型：
--
作者：
Wei Zhongzhe;Mao Shanjun;Sun Fanfei;Wang Jing;Mei Bingbao;Chen Yiqing;Li Haoran;Wang Yong
硝基芳烃催化生成功能化苯胺是合成药品、农用化学品和精细化学品的核心技术。然而，对含有一个或多个可还原基团的芳香硝基底物的化学选择性控制仍然提出了特别的挑战。本文报道了低成本合成多孔碳负载的CoS2催化剂（CoS2/PC），并成功应用于硝基芳烃的化学选择性加氢反应。对于3-硝基苯乙烯的加氢反应，该催化剂对3-氨基苯乙烯的选择性为99%，转化率为99%。密度泛函理论计算和x射线吸收精细结构光谱分析表明，co2中的三齿状和四面体配位Co原子（标记为Co3和Co4）可能是活性位点。面对面定位的Co3和Co4位点使得反应局部化，Co3和Co4位点分别被底物和H2占据，这有利于较好的活性和选择性。co2中的Co3-Co4“协同活性位点对”使得在分子水平上研究非均相催化剂的协同效应成为现实。
Catalytic functionalized aniline formation from nitroarenes is a core technology in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals. However, control of chemoselectivity still poses particular challenges with aromatic nitro substrates bearing one or more reducible groups. Here, we report the low-cost synthesis of a porous carbon supported CoS2 catalyst (CoS2/PC) and successfully apply the catalyst in the chemoselective hydrogenation of nitroarenes. For hydrogenation of 3-nitrostyrene, the catalyst furnishes a superior selectivity of 99% towards 3-aminostyrene at a conversion of >99%. Density functional theory calculations together with X-ray absorption fine structure spectroscopy reveal that terdentate and tetrahedral coordinated Co atoms in CoS2 (labeled as Co3 and Co4) are possible active sites. The face to face located Co3 and Co4 sites make the reaction rather local, and Co3 and Co4 sites are occupied by substrates and H2, respectively, which is beneficial to the superior activity and selectivity. The Co3–Co4 “synergic active site pair” in CoS2 makes the investigation of the synergic effects at the molecular level a reality on heterogeneous catalysts.