催化学报 ›› 2026, Vol. 82: 301-311.DOI: 10.1016/S1872-2067(25)64856-X

• 论文 • 上一篇    下一篇

H-ZSM-5分子筛内C1催化过程中芳烃生成的选择性控制机制

辛欣a,b, 高鹏a,b,c,*(), 李圣刚a,b,c,d,*()   

  1. a中国科学院上海高等研究院, 低碳转化科学与工程中心, 上海 201210
    b中国科学院大学, 北京 100049
    c中国科学院上海高等研究院, 低碳催化与二氧化碳利用全国重点实验室, 上海 201210
    d上海科技大学物质科学与技术学院, 上海 201210
  • 收稿日期:2025-07-03 接受日期:2025-09-16 出版日期:2026-03-18 发布日期:2026-03-05
  • 通讯作者: * 电子信箱: gaopeng@sari.ac.cn (高鹏),lisg@sari.ac.cn (李圣刚).
  • 基金资助:
    国家重点研发计划(2024YFB4206103);中国国家自然科学基金(22293023);中国国家自然科学基金(22172188);中国国家自然科学基金(22172189);中国国家自然科学基金(22293025);中国科学院青年跨学科团队, 上海市学术带头人项目(22XD1424100);上海市科学技术委员会(23YF1453400);上海市科学技术委员会(23ZR1481700)

Selectivity control mechanism of aromatics formation in C1 catalysis within H-ZSM-5 zeolites

Xin Xina,b, Peng Gaoa,b,c,*(), Shenggang Lia,b,c,d,*()   

  1. aLow-Carbon Conversion Science and Engineering Center, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
    bUniversity of Chinese Academy of Sciences, Beijing 100049, China
    cState Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
    dSchool of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
  • Received:2025-07-03 Accepted:2025-09-16 Online:2026-03-18 Published:2026-03-05
  • Contact: * E-mail: gaopeng@sari.ac.cn (P. Gao),lisg@sari.ac.cn (S. Li).
  • Supported by:
    National Key R&D Program of China(2024YFB4206103);National Natural Science Foundation of China(22293023);National Natural Science Foundation of China(22172188);National Natural Science Foundation of China(22172189);National Natural Science Foundation of China(22293025);CAS Youth Interdisciplinary Team, the Program of Shanghai Academic Research Leader(22XD1424100);Science and Technology Commission of Shanghai Municipality(23YF1453400);Science and Technology Commission of Shanghai Municipality(23ZR1481700)

摘要:

利用CO2等碳基资源, 可在减少石油资源消耗的情况下生产重要有机化学品、合成材料和燃料添加剂. 在甲醇转化和CO/CO2加氢反应中, 分子筛(特别是中孔H-ZSM-5)的酸性位点是实现芳烃选择性生成的关键活性中心. H-ZSM-5的酸性位点可分布在其MFI拓扑结构的直孔道、正弦孔道和交叉位点处, 所生成的芳烃可通过分子筛孔道扩散到催化剂表面. 在此类反应中, 甲醇、甲氧基、二甲醚等C1物种在催化过程中可作为反应物或中间体促进活性烃池物种的生成和转化. 尽管分子筛的限域效应被普遍认为是实现芳烃选择性的关键, 但关键反应步骤及甲醇或其他C1中间体的作用仍不清晰. 因此, 阐明甲醇转化为芳烃的反应路径具有重要意义, 这使得通过调节芳烃/烯烃双循环烃池机理中的烃池物种来优化芳烃合成过程成为可能.

本文通过系统的第一性原理计算, 阐明了在H-ZSM-5分子筛中具有代表性的烯烃反应中间体丙烯与含氧化合物甲醇反应形成芳烃的机制, 该低碳烯烃中间体会经历链增长、环形成和环甲基化, 从而生成各种芳烃. 结果表明, 上述反应步骤的能垒会越来越高, 其中芳环通过甲醇甲基化反应形成质子化的多甲基苯最为困难. 这在很大程度上可归因于两个因素: 一是分子筛的限域效应, 即甲醇对芳环的甲基化比对碳链的甲基化有更高的空间要求; 二是芳烃甲基化反应破坏了其芳香性. 该理论预测与近期实验观察一致, 向稳态催化系统中投入碳标记的甲醇时, 碳标记的产物首先出现在烯烃组分中, 而碳标记的芳烃组分的出现则会有较长的延时. 计算结果也很好地解释了通过共进料芳烃物种可提高特定芳烃产量, 该过程改变烃池物种的组成和抑制碳链的增长, 从而增强芳烃烷基化反应, 促进特定芳烃的生成.

综上, 该研究结果对理解芳烃的形成和甲醇的作用, 以及开发具有增强性能的分子筛基催化剂至关重要, 有助于从各种C1原料出发合成芳烃.

关键词: C1转化, 芳烃合成, H-ZSM-5分子筛, 限域效应, Brönsted酸

Abstract:

Zeolites are important components of catalysts for aromatics synthesis from methanol and CO/CO2. Although generally attributed to their confinement effects, the key reaction steps and the role of methanol or other C1 intermediates remain unclear. Herein, extensive first principles calculations were performed to reveal the mechanism of aromatics formation from light olefins such as propene and methanol within H-ZSM-5 zeolites. Propene was found to undergo chain growth, ring formation, and ring methylation, resulting in various aromatics. Our calculations show that the above steps become increasingly more difficult, so aromatic ring methylation by methanol to form protonated polymethylbenzenes was the most challenging. This can largely be attributed to both the zeolite confinement effect due to the higher spatial demand for the methylation of the aromatic ring than that of the carbon chain by methanol, and the disruption of its aromaticity. Our prediction agrees with the experimentally observed delayed formation of aromatic species, and also explains the improved production of specific aromatics by co-feeding aromatic species to change the hydrocarbon pool composition and suppress the chain growth. Thus, theoretical insights can enable the rational design of better catalysts and processes for the valorization of C1 molecules.

Key words: C1 conversion, Aromatics synthesis, H-ZSM-5 zeolites, Confinement effects, Brönsted acid