物理化学学报 >> 2025, Vol. 41 >> Issue (4): 100034.doi: 10.3866/PKU.WHXB202406012

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含硼MFI分子筛微结构调控及其丙烷氧化脱氢性能研究

李佩, 郑跃楠, 刘占凯, 陆安慧*()   

  1. 大连理工大学化工学院, 精细化工国家重点实验室, 辽宁省低碳资源高值化利用重点实验室, 辽宁 大连 116024
  • 收稿日期:2024-06-12 修回日期:2024-07-10 录用日期:2024-07-29 发布日期:2024-12-28
  • 通讯作者: Email: anhuilu@dlut.edu.cn; Tel.: +86-411-84986112 (陆安慧)
  • 基金资助:
    国家自然科学基金重点项目(21733002); 国家重点研发计划项目(2021YFA1500301); 国家自然科学基金青年基金(22302030); 中国博士后科学基金(2023M730467)

Boron-Containing MFI Zeolite: Microstructure Control and Its Performance of Propane Oxidative Dehydrogenation

Pei Li, Yuenan Zheng, Zhankai Liu, An-Hui Lu*()   

  1. State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Liaoning Key Laboratory for Catalytic Conversion of Carbon Resources, Dalian University of Technology, Dalian 116024, Liaoning Province, China
  • Received:2024-06-12 Revised:2024-07-10 Accepted:2024-07-29 Published:2024-12-28
  • Contact: Email: anhuilu@dlut.edu.cn; Tel.: +86-411-84986112 (An-Hui Lu)
  • Supported by:
    the State Key Program of National Natural Science Foundation of China(21733002); National Key Research and Development Project(2021YFA1500301); National Science Foundation for Young Scientists of China(22302030); China Postdoctoral Science Foundation(2023M730467)

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摘要：

含硼分子筛可催化丙烷氧化脱氢(ODHP)制丙烯。提升含硼分子筛中活性硼氧物种的数量以及调控硼氧物种的落位形式是开发高效硼基催化剂面临的主要挑战。本文通过尿素辅助的水热合成法制备了暴露(010)晶面的片状MFI型含硼分子筛催化剂(BMFI)。研究表明，适量添加尿素可调控分子筛形貌，其短b轴片状结构增强活性硼位点的可及性，并通过氢键作用锚定更高含量的活性硼氧物种，显著提升催化剂的ODHP活性和烯烃选择性。在520 ℃下的丙烷转化率达到20%，丙烯选择性为62.3%，总烯烃选择性为81.3%。与不加尿素形成的椭球型含硼催化剂相比，片状BMFI催化剂的丙烷反应速率提高了近20倍。片状BMFI具有更多的骨架四配位硼(B[4])和缺陷型硼物种(B[3]a和B[3]b)，反应过程中发生了活性硼结构演变，B[3]a和B[3]b是催化反应的活性位点。本研究为低碳烷烃氧化脱氢硼基催化剂的结构设计调控提供了参考。

关键词: 烷烃脱氢, 丙烷氧化脱氢, 硼基催化剂, 分子筛, 尿素, 形貌调控

Abstract:

Boron-containing zeolites can catalyze the oxidative dehydrogenation of propane (ODHP) to produce propylene. Enhancing the quantity of active boron-oxygen species and regulating the positioning of these species within the zeolite are the main challenges in developing efficient boron-based catalysts. In this study, a boron-containing zeolite catalyst with exposed (010) crystal facets, referred to as the MFI-type boron-containing zeolite (BMFI), was synthesized using a urea-assisted hydrothermal method. The research indicates that the addition of an appropriate amount of urea can regulate the morphology of the zeolite, with its short-axis flake-like structure enhancing the accessibility of active boron sites and anchoring a higher content of active boron-oxygen species through hydrogen bonding, which significantly improves the ODHP activity and olefin selectivity of the catalyst. The propane conversion rate reached 20%, with a propylene selectivity of 62.3% and a total olefin selectivity of 81.3% at 520 ℃. Compared to the ellipsoidal boron-containing catalyst formed without urea, the flake-like BMFI catalyst exhibited nearly a 20-fold increase in the reaction rate of propane. The flake-like BMFI possesses a greater number of framework tetrahedrally coordinated boron (B[4]) and defective boron species (B[3]a and B[3]b), and active boron structural evolution occurred during the reaction process, with B[3]a and B[3]b being the active sites for the catalytic reaction. This study provides a reference for the structural design and regulation of boron-based catalysts for the oxidative dehydrogenation of light alkanes.

Key words: Alkane dehydrogenation, Oxidative dehydrogenation of propane, Boron-based catalyst, Zeolite, Urea, Morphology regulation