A series of trimetallic Pt–Sn–Ce catalysts supported on chloride Al₂O₃ was prepared by a sequential impregnation method and applied for n-heptane reforming and characterized by several techniques, including N₂ physiosorption, transmission electron microscopy, X-ray diffraction, hydrogen temperature-programmed reduction, CO chemisorption, ammonia temperature-programmed desorption, pyridine desorption Fourier-transform infrared spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy. We have demonstrated that the introduction of Ce can promote isomerization reactions by suppressing undesirable hydrogenolysis reactions, whereas it does not significantly influence the dehydrocyclization reactions. The characterization results show that CeO_x can enhance the reducibility of Pt species via enhancing the Pt dispersion. In addition, Ce increases the proportion of medium-strength acid sites, which does not only promote isomerization activity, but also suppresses the undesirable reactions such as hydrogenolysis and cracking.

中文翻译：

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铈掺杂对正庚烷重整的Pt-Sn / Al ₂ O ₃催化剂的影响

通过顺序浸渍法制备了一系列负载在氯化物Al ₂ O ₃上的三金属Pt-Sn-Ce催化剂，并用于正庚烷重整，并通过包括N ₂在内的多种技术进行了表征。物理吸附，透射电子显微镜，X射线衍射，氢程序升温还原，CO化学吸附，氨程序升温解吸，吡啶解吸傅里叶变换红外光谱和原位漫反射红外傅里叶变换光谱。我们已经证明，Ce的引入可以通过抑制不希望的氢解反应来促进异构化反应，而它不会显着影响脱氢环化反应。表征结果表明CeO _x可以通过增强Pt分散性来增强Pt物种的还原性。另外，Ce增加了中强度酸位点的比例，这不仅促进了异构化活性，而且抑制了诸如氢解和裂化之类的不良反应。