高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (6): 20220778.doi: 10.7503/cjcu20220778

• 物理化学 • 上一篇    下一篇

树状PAMAM改性纳米二氧化硅负载镍催化剂的制备及催化乙烯齐聚性能

黄金1,2, 郭丽君2, 李锋2, 李杨2, 李翠勤2()   

  1. 1.大庆师范学院黑龙江省油田应用化学与技术省重点实验室, 大庆 163712
    2.东北石油大学化学化工学院, 黑龙江省聚烯烃新材料省重点实验室, 大庆 163318
  • 收稿日期:2022-12-31 出版日期:2023-06-10 发布日期:2023-02-17
  • 通讯作者: 李翠勤 E-mail:dqpilicuiqin@126.com
  • 基金资助:
    黑龙江省重点研发项目(JD22A026);黑龙江省自然科学基金(E2018012)

Preparation and Catalytic Behavior in Ethylene Oligomerization of Nickel Catalyst Supported by Dendritic PAMAM Functionalized Nano-silica

HUANG Jin1,2, GUO Lijun2, LI Feng2, LI Yang2, LI Cuiqin2()   

  1. 1.Heilongjiang Provincial Key Laboratory of Oilfield Applied Chemistry and Technology,Daqing Normal University,Daqing 163712,China
    2.Heilongjiang Provincial Key Laboratory of Polyolefin New Materials,College of Chemistry & Chemical Engineering,Northeast Petroleum University,Daqing 163318,China
  • Received:2022-12-31 Online:2023-06-10 Published:2023-02-17
  • Contact: LI Cuiqin E-mail:dqpilicuiqin@126.com
  • Supported by:
    the Heilongjiang Key Research and Development Project, China(JD22A026);the Heilongjiang Province Natural Science Foundation, China(E2018012)

摘要:

以纳米二氧化硅为载体, 树状聚酰胺-胺(PAMAM)镍络合物为催化活性中心, 通过共价负载制备了一种具有良好催化活性和循环利用性的PAMAM改性纳米二氧化硅负载镍催化剂(化合物G). 采用元素分析、 傅里叶变换红外光谱(FTIR)、 X射线衍射(XRD)和扫描电子显微镜(SEM)表征了化合物G的组成及形貌. 研究了该类负载镍催化剂催化乙烯齐聚的性能, 考察了齐聚条件对其性能的影响. 结果表明, 化合物G具有良好的催化乙烯齐聚活性和循环利用性. 基于灰色关联分析得出反应压力是影响乙烯齐聚活性的最主要因素, 反应温度是影响乙烯齐聚选择性的最主要因素. 当以甲基铝氧烷(MAO)为助催化剂, 反应压力0.7 MPa, n(Al)/n(Ni)为500, 反应温度为35 ℃, 主催化剂用量为5 μmol时, 化合物G催化乙烯齐聚活性为3.75×105 g/(mol Ni·h), 齐聚产物中C4~C8烯烃选择性为94.98%. 化合物G的树状效应使其金属负载量、 催化乙烯齐聚活性和C8烯烃的选择性均高于氨基化改性纳米二氧化硅负载镍(化合物E); 且化合物G经3次回收循环使用后, 催化乙烯齐聚活性为3.12×105 g/(mol Ni·h), 齐聚产物中C8烯烃选择性为36.37%.

关键词: 树状聚酰胺-胺, 乙烯齐聚, 树状效应, 负载催化剂

Abstract:

Nano-silica supported nickel catalyst(compound G) with good catalytic activity and reusability was prepared through anchoring via covalent binding of dendritic poly(amido amine)(PAMAM) in nano-silica. The composition and the morphology of compound G were verified by elemental analysis, Fourier transform infrared spectrophotometer(FTIR), inductively coupled plasma(ICP), X-ray diffraction(XRD) and scanning electron microscopy(SEM). The catalytic behavior of compound G in ethylene oligomerization was evaluated and the effect of oligomerization parameters on the catalytic properties of compound G was investigated. The results showed that compound G had good catalytic properties and repeatability. Based on the grey correlation analysis, it was found that the reaction pressure was the most important factor affecting the activity of ethylene oligomerization, and the reaction temperature was the most important factor affecting the selectivity of ethylene oligomerization. When the methylaluminoxane(MAO) was cocatalyst, the dosage of compound G was 5 μmol, the molar ratio of Al/Ni was 500, reaction pressure was 0.7 MPa, reaction time was 30 min and reaction temperature was 35 ℃, the catalytic activity was 3.85×105 g/(mol Ni·h) and the selectivity of C4—C8 olefins was 94.98%. The nickel content, the catalytic activity and the selectivity of C8 olefin for compound G were higher than nickel catalyst supported by amino modified nano-silica (compound E) due to dendritic effect. And the catalytic activity of compound G was 3.12×105 g/(mol Ni·h) and the selectivity of C8 olefin was 36.37% after the third oligomerization reaction.

Key words: Dendritic poly(amido amine), Ethylene oligomerization, Dendritic effect, Heterogeneous catalyst

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