Non-noble metal catalysts for hydrogenation: A facile method for preparing Co nanoparticles covered with thin layered carbon
Non-noble metal catalysts for hydrogenation: A facile method for preparing Co nanoparticles covered with thin layered carbon
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DOI：
10.1016/j.jcat.2016.04.006
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发表时间：
2016-08-01
影响因子：
7.3
通讯作者：
Corma, Avelino
中科院分区：
文献类型：
--
作者：
Liu, Lichen;Concepcion, Patricia;Corma, Avelino
利用Co-EDTA配合物的热分解直接合成了表面覆盖薄层碳的cox贴片的金属钴纳米颗粒（命名为Co@C）。拉曼光谱和HRTEM图像表明，在无序层状碳中可以发现不连续性。XPS结果表明，在120℃7 bar的反应条件下，Co@C纳米颗粒中的CoOx斑块可以被H-2还原为金属Co， H-2- d -2交换实验表明，被碳层覆盖的还原金属Co纳米颗粒可以解离H-2。在温和的反应条件下，Co@C纳米颗粒在广泛的底物上对硝基芳烃进行化学选择性加氢，表现出优异的活性和选择性。根据DRIFTS吸附实验结果，我们认为Co@C纳米颗粒中的金属Co是活性相。碳层的作用是保护Co不被空气过度氧化，从而导致硝基芳烃的化学选择性加氢。(C) 2016 Elsevier Inc.版权所有。
Metallic cobalt nanoparticles with surface CoOx patches covered by thin layered carbon (named Co@C) have been directly synthesized by thermal decomposition of Co-EDTA complex. Raman spectra and HRTEM images suggest that discontinuities can be found in the disordered layered carbon. XPS shows that the CoOx patches in the Co@C nanoparticles can reduced to metallic Co by H-2 under reaction conditions (7 bar at 120 degrees C), and H-2-D-2 exchange experiments show that the reduced metallic Co nanoparticles covered by carbon layers can dissociate H-2. The Co@C nanoparticles show excellent activity and selectivity during chemoselective hydrogenation of nitroarenes for a wide scope of substrates under mild reaction conditions. Based on the results from DRIFTS adsorption experiments, we propose that metallic Co in the Co@C nanoparticles is the active phase. The role of the carbon layers is to protect the Co from overoxidation by air, leading to the chemoselective hydrogenation of nitroarenes. (C) 2016 Elsevier Inc. All rights reserved.