Zhao Jianbo, Yuan Haifeng, Li Jiangcun, Bing Wanzhen, Yang Weichuang, Liu Yingfan, Chen Junli, Wei Chengzhen, Zhou Liming, Fang Shaoming
School of Material and Chemical Engineering, Zhengzhou University of Light Industry, No. 136 of Science Road, Zhengzhou 450001, P. R. China.
Institute of Chemical Defence, P.O. Box 1048, Beijing 102205, P. R. China.
ACS Omega. 2020 Mar 18;5(12):7011-7017. doi: 10.1021/acsomega.0c00364. eCollection 2020 Mar 31.
Effects of preparation parameters of NiAl oxide-supported Au nanocatalysts on their performance in the chemoselective hydrogenation of nitro compounds were investigated. The deposition-precipitation method, low Au loading, and low Ni/Al molar ratio of the support contributed to the generation of small-sized Au nanoparticles. High catalytic properties were related to the small sizes of Au particles and appropriate basicity of supports. Accordingly, the 0.43% Au/NiAlO-2-500 (the Ni/Al molar ratio of the support = 2) showed high activity and excellent selectivity for nitro hydrogenation. It also showed good versatility for other nitro compounds and good recyclability. Interestingly, for the first time, this Au catalyst switched its selectivity to vinyl hydrogenation by mere regulation of the composition of the support (the Ni/Al molar ratio of the support = 4). The observed shift in selectivity was ascribed to the different adsorption behaviors of the nitro and vinyl group on Au nanocatalysts. It provides a novel and facile strategy to construct Au nanocatalysts with high activity and switchable selectivity for hydrogenation of nitro compounds by the fine tuning of preparation parameters.
研究了NiAl氧化物负载的Au纳米催化剂的制备参数对其在硝基化合物化学选择性加氢反应中性能的影响。沉积沉淀法、低Au负载量以及载体的低Ni/Al摩尔比有助于生成小尺寸的Au纳米颗粒。高催化性能与Au颗粒的小尺寸和载体合适的碱性有关。因此，0.43%Au/NiAlO-2-500（载体的Ni/Al摩尔比 = 2）对硝基加氢显示出高活性和优异的选择性。它对其他硝基化合物也表现出良好的通用性和良好的可回收性。有趣的是，首次通过简单调节载体组成（载体的Ni/Al摩尔比 = 4），这种Au催化剂将其选择性转变为乙烯基加氢。观察到的选择性变化归因于硝基和乙烯基在Au纳米催化剂上不同的吸附行为。通过精细调节制备参数，为构建具有高活性和可切换选择性的用于硝基化合物加氢的Au纳米催化剂提供了一种新颖且简便的策略。
