High Catalytic Activity and Chemoselectivity of Sub-nanometric Pd Clusters on Porous Nanorods of CeO2 for Hydrogenation of Nitroarenes.
High Catalytic Activity and Chemoselectivity of Sub-nanometric Pd Clusters on Porous Nanorods of CeO2 for Hydrogenation of Nitroarenes.
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DOI：
10.1021/jacs.5b11413
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发表时间：
2016-02
影响因子：
15
通讯作者：
Sai Zhang;Chunran Chang;Zheng-Qing Huang;Jing Li;Zhemin Wu;Yuanyuan Ma;Zhiyun Zhang;Yong Wang-
中科院分区：
文献类型：
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作者：
Sai Zhang;Chunran Chang;Zheng-Qing Huang;Jing Li;Zhemin Wu;Yuanyuan Ma;Zhiyun Zhang;Yong Wang-
在具有73.6%高钯分散度的二氧化铈（PN - CeO₂）多孔纳米棒上的亚纳米钯簇展现出了迄今为止对硝基芳烃加氢反应最高的催化活性和最佳的化学选择性。对于对硝基苯酚的加氢反应，该催化剂的转换频率（TOF）约为44059 h⁻¹，对4 - 氨基苯酚的化学选择性>99.9%。这种优异的催化性能可归因于高分散的亚纳米钯簇用于氢活化以及具有高浓度氧空位的PN - CeO₂独特表面位点之间的协同效应，这种协同效应使得硝基芳烃能够通过硝基在能量和几何结构上优先吸附。PN - CeO₂表面缺陷的高浓度和较大的钯分散度有助于提高加氢反应的催化活性。高化学选择性主要由载体上的高钯分散度决定。该催化剂对于具有各种可还原取代基的硝基芳烃加氢生成相应的氨基芳烃也表现出高催化活性和选择性。
Sub-nanometric Pd clusters on porous nanorods of CeO2 (PN-CeO2) with a high Pd dispersion of 73.6% exhibit the highest catalytic activity and best chemoselectivity for hydrogenation of nitroarenes to date. For hydrogenation of 4-nitrophenol, the catalysts yield a TOF of ∼44059 h(-1) and a chemoselectivity to 4-aminophenol of >99.9%. The superior catalytic performance can be attributed to a cooperative effect between the highly dispersed sub-nanometric Pd clusters for hydrogen activation and unique surface sites of PN-CeO2 with a high concentration of oxygen vacancy for an energetically and geometrically preferential adsorption of nitroarenes via nitro group. The high concentration of surface defects of PN-CeO2 and large Pd dispersion contribute to the enhanced catalytic activity for the hydrogenation reactions. The high chemoselectivity is mainly governed by the high Pd dispersion on the support. The catalysts also deliver high catalytic activity and selectivity for nitroaromatics with various reducible substituents into the corresponding aminoarenes.