Abstract

Cu–Ni/SiO₂ catalysts were prepared by coprecipitation method and used in the dehydrogenation reaction of secondary butyl alcohol to methyl ethyl ketone (MEK). The crystal structure, reduction characteristics, element valence state and dispersibility of the catalysts were investigated using X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H₂-TPR), inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), X-ray Auger electron spectroscopy (XAES) and high resolution transmission electron microscopy (HRTEM). The role of Ni component in the dehydrogenation reaction of secondary butyl alcohol was analyzed. The results showed that the conversion of secondary butyl alcohol increased to over 99% when using the Cu–Ni/SiO₂ catalyst. The addition of nickel component to Cu/SiO₂ inhibited the agglomeration of copper nanoparticles. The interaction between copper and nickel was strengthened due to the formation of the Cu–Ni compound. This resulted in change to the valence state and improved the dispersion of copper species on the catalyst surface. The Cu⁺/(Cu⁺ + Cu⁰) ratio increased with the addition of nickel component to Cu/SiO₂, which may be responsible for the enhancement of the secondary butyl alcohol conversion. However, the addition of the nickel component increased the reduction temperature of the catalysts and deteriorated their reduction characteristics, which leads to insufficient reduction, resulting in a high content of Cu⁺ species remaining in the catalyst. Therefore, side reactions can occur, which are detrimental to the selectivity and yield of MEK. The selectivity to MEK can reach 98% with the Cu/SiO₂ catalyst, whereas that for the Cu–Ni/SiO₂ catalyst was 97%.

中文翻译：

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Cu-Ni/SiO2 催化剂用于仲丁醇脱氢反应

摘要

采用共沉淀法制备了Cu-Ni/SiO ₂催化剂，并将其用于仲丁醇脱氢制丁酮(MEK)的反应。_{采用X射线衍射(XRD)、氢气程序升温还原(H 2} -TPR)、电感耦合等离子体发射光谱(ICP-OES)等手段研究了催化剂的晶体结构、还原特性、元素价态和分散性。 X 射线光电子能谱 (XPS)、X 射线俄歇电子能谱 (XAES) 和高分辨率透射电子显微镜 (HRTEM)。分析了Ni组分在仲丁醇脱氢反应中的作用。_{结果表明，使用Cu-Ni/SiO 2}催化剂时，仲丁醇的转化率提高到99%以上。_{Cu/SiO 2}中添加镍成分抑制了铜纳米颗粒的团聚。由于铜镍化合物的形成，铜和镍之间的相互作用得到加强。这导致价态的变化并改善了铜物质在催化剂表面上的分散。_{随着Cu/SiO 2}中镍组分的添加，Cu ⁺ /(Cu ⁺ + Cu ⁰ )比率增加，这可能是仲丁醇转化率提高的原因。然而，镍组分的添加提高了催化剂的还原温度，降低了其还原特性，导致还原不充分，导致催化剂中残留的Cu ^{+物质含量较高。}因此，可能会发生副反应，这不利于 MEK 的选择性和产率。_{Cu/SiO 2}催化剂对MEK的选择性可以达到98% ，而Cu-Ni/SiO ₂催化剂的选择性为97%。