硝基苯
催化作用
苯胺
介孔材料
选择性
活性炭
材料科学
化学工程
色散(光学)
镍
多孔性
炭黑
化学
无机化学
核化学
有机化学
吸附
冶金
复合材料
物理
天然橡胶
光学
工程类
作者
Hexin Jiang,Guanming Yuan,Zhengwei Cui,Zi Hao Zhao,Zhijun Dong,Zhang Jiang,Ye Cong,Xuanke Li
标识
DOI:10.1021/acs.iecr.3c01327
摘要
Ni-based catalysts are increasingly being used in nitrobenzene hydrogenation. How to select suitable catalyst supports is crucial for upgrading the catalytic performance. Herein, three Ni-based catalysts supported on activated carbon fiber (ACF), mesoporous carbon black (CB), and γ-Al2O3 were tested for nitrobenzene hydrogenation. The influence of catalyst supports, their porosity characteristics, and reaction conditions on the catalytic performance was investigated. The results show that 10 wt % Ni/CB catalyst owns an ultrafine active Ni nanoparticles (∼10 nm) with a uniform dispersion and thus exhibits the optimal catalytic activity. The conversion of nitrobenzene and the selectivity to aniline could reach nearly 100% at 120 °C for 1 h. By contrast, it takes 2 h to achieve the same conversion for 10 wt % Ni/ACF at 120 °C, whereas 10 wt % Ni/Al2O3 needs a severe reaction at 150 °C for 2 h. The turnover frequency of 10 wt % Ni/CB approaches 38 h–1, which is higher than those of other catalysts. Nitrobenzene hydrogenation over different catalysts conforms to a first-order reaction, and the apparent activation energy of 10 wt % Ni/CB (42.6 kJ/mol) is significantly lower than that of 10 wt % Ni/Al2O3 (66.0 kJ/mol). Moreover, 10 wt % Ni/CB catalyst exhibits a good recyclability and structural stability owing to the existence of abundant mesopores in CB, in comparison with 10 wt % Ni/ACF and Ni/Al2O3. It is the mesopores rather than the micropores in carbon supports to postpone the deactivation of Ni-based catalysts. This work demonstrates the superiority of porous carbons as catalyst supports over Al2O3 in nitrobenzene hydrogenation.
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