化工学报 ›› 2025, Vol. 76 ›› Issue (10): 5128-5140.DOI: 10.11949/0438-1157.20250335

• 催化、动力学与反应器 • 上一篇    下一篇

高分散双位点Co物种协同催化CO2氧化乙烷脱氢制乙烯的研究

金雨昕1(), 吴文莉1, 童婳1, 叶代启1,2,3, 陈礼敏1,2,3()   

  1. 1.华南理工大学环境与能源学院,广东 广州 510006
    2.挥发性有机物污染治理技术与装备国家工程实验室,广东 广州 510006
    3.广东省大气环境与污染控制重点实验室,广东 广州 510006
  • 收稿日期:2025-04-02 修回日期:2025-06-23 出版日期:2025-10-25 发布日期:2025-11-25
  • 通讯作者: 陈礼敏
  • 作者简介:金雨昕(2000—),女,硕士研究生,1005458648@qq.com
  • 基金资助:
    国家自然科学基金项目(22276060);广东省基础与应用基础研究基金项目(2024A1515012636)

Study on synergistic catalysis by highly dispersed dual-site Co species for CO2-oxidative dehydrogenation of ethane to ethylene

Yuxin JIN1(), Wenli WU1, Hua TONG1, Daiqi YE1,2,3, Limin CHEN1,2,3()   

  1. 1.School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China
    2.National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangzhou 510006, Guangdong, China
    3.Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, Guangzhou 510006, Guangdong, China
  • Received:2025-04-02 Revised:2025-06-23 Online:2025-10-25 Published:2025-11-25
  • Contact: Limin CHEN

摘要:

为了获得具有高CO2氧化乙烷脱氢制乙烯活性的Co基催化剂,依次通过离子交换法及浸渍法制备了一系列Co/SSZ-13催化剂。通过Raman、XPS等表征手段探究了Co物种的落位和价态,并基于本课题组提出的反应路径分析方法揭示了高分散双位点Co物种协同催化CO2氧化乙烷脱氢制乙烯的机理。结果表明,在离子交换法基础上通过浸渍在催化剂上二次负载Co物种能够有效提升催化剂活性,675℃时乙烯收率由23.46%升至38.20%;离子交换法主要在分子筛上锚定高度分散的Co(Ⅱ)物种,其表现出良好的直接脱氢活性;在此基础上进行浸渍能够在表面负载Co3O4物种,其在反应过程中还原为Co0物种从而促进逆水煤气反应,进而提升催化剂的表观氧化脱氢性能。然而,当浸渍负载量过高时,Co3O4物种在反应过程中原位还原为低分散度的Co0物种,降低了催化剂乙烯选择性。本文揭示了双位点Co物种的协同机制,指出需精准调控催化剂原始双位点比例以兼顾活性和稳定性。

关键词: CO2, 乙烷, 氧化脱氢, 化学反应, 催化剂, 分子筛

Abstract:

To obtain a Co-based catalyst with high-activity for CO2-assisted ethane dehydrogenation to ethylene, a series of Co/SSZ-13 catalysts were prepared by ion-exchange and impregnation methods. Raman and XPS were employed to investigate the coordination environment and valence state of Co species, while reaction pathway analysis revealed the synergistic mechanism of highly dispersed dual-site Co species in catalyzing the reaction. The additional impregnation step following ion-exchange significantly enhanced catalytic activity, increasing ethylene yield from 23.46% to 38.20% at 675℃. Ion-exchange method primarily anchored highly dispersed Co(Ⅱ) species on SSZ-13, which exhibited excellent ethane direct dehydrogenation (EDH) activity. Subsequent impregnation increased the content of Co3O4, which promoted the reverse water-gas shift (RWGS) reaction because of the in situ reduction to Co0 during reaction evaluation and synergistically improved the apparent oxidative dehydrogenation (ODHE) performance with Co(Ⅱ). However, excessive Co3O4 content induced excessive Co0 species during catalytic evaluation process, leading to severe side reactions and reduced selectivity to ethylene. This work elucidates the cooperative mechanism of dual-site Co species and demonstrates the necessity of precisely tuning the ratio of dual-sites of the fresh catalysts to balance activity and stability.

Key words: CO2, ethane, oxidative dehydrogenation, chemical reaction, catalyst, molecular sieves

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