化工学报 ›› 2024, Vol. 75 ›› Issue (9): 3188-3197.DOI: 10.11949/0438-1157.20240318

• 催化、动力学与反应器 • 上一篇    下一篇

薄片状PtZn@Silicalite-1分子筛的合成及催化丙烷脱氢性能研究

王靖宇1,2(), 刘佳1,2(), 徐继香1,2(), 王磊1,2   

  1. 1.生态化工国家重点实验室培育基地,山东 青岛 266042
    2.青岛科技大学化学与分子工程学院,山东 青岛 266042
  • 收稿日期:2024-03-20 修回日期:2024-04-26 出版日期:2024-09-25 发布日期:2024-10-10
  • 通讯作者: 刘佳,徐继香
  • 作者简介:王靖宇(1997—),男,硕士研究生,wjy04271997@163.com
  • 基金资助:
    山东省自然科学基金项目(ZR2020QB054)

Synthesis of lamellar PtZn@Silicalite-1 zeolite and its catalytic properties for propane dehydrogenation

Jingyu WANG1,2(), Jia LIU1,2(), Jixiang XU1,2(), Lei WANG1,2   

  1. 1.Key Laboratory of Eco-chemical Engineering, Qingdao 266042, Shandong, China
    2.College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong, China
  • Received:2024-03-20 Revised:2024-04-26 Online:2024-09-25 Published:2024-10-10
  • Contact: Jia LIU, Jixiang XU

摘要:

采用水热晶化法,以四甲基胍(TMG)为形貌调控剂,一步合成封装PtZn纳米合金的薄片状Silicalite-1分子筛(PtZn@Silicalite-1)。采用X射线衍射(XRD)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等技术对样品进行表征分析,并考察了其丙烷脱氢催化性能。结果显示,加入TMG可有效调控Silicalite-1分子筛晶体的生长取向,晶体沿b轴的尺寸与TMG/SiO2的比值呈反比。在550℃和纯丙烷气氛下,片状PtZn@Silicalite-1催化剂表现出优异的丙烷脱氢性能,经过20 h的连续反应,其失活常数仅为0.007 h-1,而常规PtZn@Silicalite-1催化剂为0.013 h-1。结合表征结果,薄片状分子筛催化剂具有更大的外比表面积和更短的b轴直通道,这提高了脱氢活性位的可接近性,缩短了气体分子在孔道中的扩散路径,从而提升了催化剂的活性和稳定性。

关键词: 薄片形貌, Silicalite-1分子筛, PtZn合金, 封装, 丙烷脱氢

Abstract:

The lamellar Silicalite-1 zeolite (PtZn@Silicalite-1) encapsulated PtZn nano-alloy was synthesized in one step by hydrothermal crystallization method with tetramethylguanidine (TMG) as morphology regulator. The catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), and their catalytic performance for propane dehydrogenation was investigated. The results show that the addition of TMG can effectively regulate the growth orientation of Silicalite-1 zeolite crystals, and the crystal size along the b-axis is inversely proportional to the ratio of TMG/SiO2. At 550℃ and in pure propane atmosphere, the lamellar PtZn@Silicalite-1 catalyst showed excellent propane dehydrogenation performance. After 20 h of continuous reaction, its deactivation constant was only 0.007 h-1, while that of the conventional PtZn@Silicalite-1 catalyst was 0.013 h-1. Combined with the characterization data, the lamellar zeolite catalyst has larger external specific surface area and shorter b-axis through channel, which improves the accessibility of the dehydrogenation active site and shortens the diffusion path of gas molecules in the pore, thus improving the activity and stability of the catalyst.

Key words: lamellar shape, Silicalite-1 zeolite, PtZn alloy, encapsulation, propane dehydrogenation

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