催化学报 ›› 2025, Vol. 68: 246-258.DOI: 10.1016/S1872-2067(24)60166-X

• 论文 • 上一篇    下一篇

MFI介孔分子筛限域封装Co纳米颗粒选择性催化合成气转化为重质液态烃燃料

龚能a,1, 邓权政a,1, 王雨娇b, 王自陶c, 韩璐a,*(), 吴鹏d,*(), 车顺爱e,*()   

  1. a同济大学化学科学与工程学院, 上海 200092
    b重庆大学化学化工学院, 前沿交叉学科研究院, 跨尺度多孔材料研究中心, 重庆 400044
    c吉林大学无机合成与制备化学国家重点实验室, 吉林长春 130015
    d华东师范大学化学与分子工程学院, 上海市绿色化学与化工过程绿色化重点实验室, 石油化工分子转化与反应工程全国重点实验室, 上海 200062
    e上海交通大学化学化工学院, 变革性分子前沿科学中心, 金属基复合材料国家重点实验室, 上海市手性药物分子工程重点实验室, 上海 200240
  • 收稿日期:2024-07-03 接受日期:2024-09-27 出版日期:2025-01-18 发布日期:2025-01-02
  • 通讯作者: * 电子信箱: chesa@sjtu.edu.cn (车顺爱), pwu@chem.ecnu.edu.cn (吴鹏), luhan@tongji.edu.cn (韩璐).
  • 作者简介:

    1共同第一作者.

  • 基金资助:
    国家自然科学基金(21931008);国家重点研发计划(2021YFA1200301);国家重点研发计划(2021YFA1501401)

Co nanoparticles confined in mesopores of MFI zeolite for selective syngas conversion to heavy liquid hydrocarbon fuels

Neng Gonga,1, Quanzheng Denga,1, Yujiao Wangb, Zitao Wangc, Lu Hana,*(), Peng Wud,*(), Shun’ai Chee,*()   

  1. aSchool of Chemical Science and Engineering, Tongji University, Shanghai 200092, China
    bMulti-scale Porous Materials Center, Institute of Advanced Interdisciplinary Studies & School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
    cState Key Laboratory of Inorganic Synthesis & Preparative Chemistry, Jilin University, Changchun 130015, Jilin, China
    dShanghai Key Laboratory of Green Chemistry and Chemical Processes, State Key Laboratory of Petroleum Molecular & Process Engineering, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
    eSchool of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, Shanghai 200240, China
  • Received:2024-07-03 Accepted:2024-09-27 Online:2025-01-18 Published:2025-01-02
  • Contact: * E-mail: chesa@sjtu.edu.cn (S. Che), pwu@chem.ecnu.edu.cn (P. Wu), luhan@tongji.edu.cn (L. Han).
  • About author:

    1Contributed equally to this work.

  • Supported by:
    National Natural Science Foundation of China(21931008);National Key R&D Program of China(2021YFA1200301);National Key R&D Program of China(2021YFA1501401)

摘要:

费托合成(FTS)能有效地将非石油基碳资源衍生的合成气(CO/H2)转化为清洁液态烃燃料. 目前FTS主要的活性金属组分是Fe, Ru和Co, 其中, Co基催化剂具有适宜的长链烃生长能力和价格低廉等优点. 采用介孔ZSM-5或者Y分子筛作为Co金属纳米颗粒(NPs)的载体, 利用分子筛固有的酸性位点, 增强传质能力和择形选择性, 将固体蜡C21+裂解为中间馏分液体燃料. 由于重质的液态烃过度裂解和氢解, 这些催化剂合成的液态产物通常是汽油烃(C5-C11). 本文通过调控Co NPs在介孔MFI分子筛中的位置分布, 抑制重质烃产物的C-C键过度裂解和氢解, 以实现煤油(C8-C16)和柴油(C10-C20)的高选择性生成.
本文采用浸渍法将Co NPs选择性地封装到有序介孔MFI分子筛(OMMZ)的微孔和介孔孔道中, 通过调控不同尺寸孔道中催化活性位点的位置, 实现了FTS产物中碳数分布的控制. 设计了醋酸盐配位Co(Co-acet) (9.4×4.2×2.5 Å)和2,2'-联吡啶配位Co(Co-bpy) (9.5×8.7×7.9 Å)两种比MFI结构的10元环孔道(5.5 Å)尺寸更小和更大的Co前驱体, 使得Co分别进入OMMZ的微孔(Co-acet/OMMZ)和介孔孔道(Co-bpy/OMMZ). X射线衍射和高分辨扫描透射电镜结果表明, 在Co-acet/OMMZ中, Co NPs主要以亚纳米纤维状限域在微孔孔道里, 直径约为0.9 nm; 在Co-bpy/OMMZ中, Co NPs主要以纳米颗粒状限域在介孔孔道中, 尺寸约为2.5 nm. 合成气转化反应结果表明, Co NPs限域在微孔和介孔孔道中的弱酸性Na型Co-acet/Na-OMMZ和Co-bpy/Na-OMMZ催化剂分别显示出66.5%的煤油选择性和65.3%的柴油选择性. Co NPs限域在具有Brönsted酸位点的H型Co-acet/H-OMMZ和Co-bpy/H-OMMZ催化剂时, 分别显示了76.7%的汽油选择性和70.8%的煤油选择性. 催化结果表明, 在Co NPs位于OMMZ有序介孔中的Co-bpy/OMMZ上形成的烃类产物碳数比位于微孔中的Co-acet/OMMZ上形成的产物碳数高, 意味着介孔中均匀分布的Co NPs可以缓解重质烃的C-C裂解, 而且Co-bpy/OMMZ的CH4选择性低于Co-acet/OMMZ, 表明介孔中的Co NPs上重质烃的氢解作用受到抑制. 几乎不含Brönsted酸的Co/Na-OMMZ有效抑制了重质烃的裂解, 其产物碳数比Co/H-OMMZ更大.
综上, 本文通过选择不同尺寸的Co前驱体, 成功地调控了有序介孔MFI分子筛中Co金属颗粒的尺寸和位置分布, 从而抑制长链烃的C-C裂解, 实现了液态烃燃料在特定碳数范围的可控分布. 该工作为设计合成直接生产重质烃燃料的FTS催化剂提供了一条有效的策略.

关键词: 费托合成, 重质液态烃燃料, Co纳米颗粒, 有序介孔MFI分子筛, C-C裂解

Abstract:

Designing Fischer-Tropsch synthesis (FTS) catalysts to selectively produce liquid hydrocarbon fuels is a crucial challenge. Herein, we selectively introduced Co nanoparticles (NPs) into the micropores and mesopores of an ordered mesoporous MFI zeolite (OMMZ) through impregnation, which controlled the carbon number distribution in the FTS products by tuning the position of catalytic active sites in differently sized pores. The Co precursors coordinated by acetate with a size of 9.4 × 4.2 × 2.5 Å and by 2,2'-bipyridine with a size of 9.5 × 8.7 × 7.9 Å, smaller and larger than the micropores (ca. 5.5 Å) of MFI, made the Co species incorporated in OMMZ's micropores and mesopores, respectively. The carbon number products synthesized with the Co NPs confined in mesopores were larger than that in micropores. The high jet and diesel selectivities of 66.5% and 65.3% were achieved with Co NPs confined in micropores and mesopores of less acidic Na-type OMMZ, respectively. Gasoline and jet selectivities of 76.7% and 70.8% were achieved with Co NPs confined in micropores and mesopores of H-type OMMZ with Brönsted acid sites, respectively. A series of characterizations revealed that the selective production of diesel and jet fuels was due to the C-C cleavage suppressing of heavier hydrocarbons by the Co NPs located in mesopores.

Key words: Fischer-Tropsch synthesis, Heavy liquid hydrocarbon fuel, Co nanoparticle, Ordered mesoporous MFI zeolite, C-C cleavage