The catalytic performances of different CuZnAl catalysts prepared using copper nitrate, copper acetate and copper citrate for CO hydrogenation to higher alcohols (C₂₊OH) were studied in a slurry bed reactor. Among these catalysts, the Cu–N catalyst prepared using copper nitrate showed a relatively higher C₂₊OH selectivity and no obvious deactivation occurred during the lifetime test for 120 h. The influence of copper precursors on the performance of the CuZnAl catalysts was investigated by XRD, ²⁷Al-MAS-NMR, N₂ adsorption–desorption, H₂-TPR, NH₃-TPD, FT-IR and XPS techniques. The results indicated that the size of Cu⁰ particles, textural properties, the chemical state of Cu species, the amount of surface acid and chemical composition varied, which led to diverse catalytic activities toward C₂₊OH synthesis. It was concluded that Cu⁰, Cu⁺ and AlOOH were all necessary in ethanol and C₂₊OH synthesis when using the CuZnAl catalysts without promoters and the synergism of these species was beneficial to the formation of C₂₊OH. This work further demonstrated that alkalis and Fischer–Tropsch elements were not indispensable for C₂₊OH synthesis from syngas.

中文翻译：

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在无助剂的CuZnAl催化剂上由合成气合成高级醇中铜前体的研究

在淤浆床反应器中研究了使用硝酸铜，乙酸铜和柠檬酸铜制备的不同CuZnAl催化剂在CO加氢成高级醇（C ₂₊ OH）方面的催化性能。在这些催化剂中，使用硝酸铜制备的Cu–N催化剂显示出相对较高的C ₂₊ OH选择性，并且在寿命测试120小时内未发生明显的失活。通过XRD，²⁷ Al-MAS-NMR，N ₂吸附-解吸，H ₂ -TPR，NH ₃ -TPD，FT-IR和XPS技术研究了铜前驱体对CuZnAl催化剂性能的影响。结果表明，Cu ⁰的大小颗粒，组织性质，Cu物种的化学状态，表面酸的量和化学组成各不相同，从而导致了对C ₂₊ OH合成的不同催化活性。得出的结论是，当使用不含助催化剂的CuZnAl催化剂时，乙醇和C ₂₊ OH合成中，Cu ⁰，Cu ⁺和AlOOH都是必需的，这些物种的协同作用有利于C ₂₊ OH的形成。这项工作进一步证明了碱和费-托元素对于合成气合成C ₂₊ OH并非必不可少。