催化学报 ›› 2026, Vol. 91: 122-134.DOI: 10.1016/S1872-2067(26)65216-3

• 论文 • 上一篇    下一篇

Zn介导调控Fe-Si相互作用实现CO2加氢反应稳定性与选择性平衡

刘意a,*(), 张鹏a,b, 李益君a,b, 韩志华a, 冯波a, 聂小娃c, 陈静允a, 何若南a, 王周君d, 邵磊b, 秦绍东a,*(), 张光辉c, 郭新闻c,*()   

  1. a 国家能源集团, 北京低碳清洁能源研究院, 北京 102211
    b 北京化工大学教育部超重力工程研究中心, 北京 100029
    c 大连理工大学化工学院, 精细化工全国重点实验室, 智能材料前沿科学中心, 大连理工大学-宾州州立大学联合能源研究中心, 辽宁大连 116024
    d 北京化工大学, 化工资源有效利用全国重点实验室, 能源环境催化北京市重点实验室, 北京 100029

Zn-mediated modulation of Fe-Si interactions to achieve a balance between stability and selectivity in CO2 hydrogenation

Yi Liua,*(), Peng Zhanga,b, Yijun Lia,b, Zhihua Hana, Bo Fenga, Xiaowa Niec, Jingyun Chena, Ruonan Hea, Zhoujun Wangd, Lei Shaob, Shaodong Qina,*(), Guanghui Zhangc, Xinwen Guoc,*()   

  1. a National Institute of Clean-and-low-carbon Energy (NICE), CHN Energy, Beijing 102211, China
    b Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029, China
    c State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, PSU-DUT Joint Center for Energy Research, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
    d State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Energy Environmental Catalysis, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2026-03-30 Accepted:2026-07-06 Online:2026-12-18 Published:2026-10-13
  • Supported by:
    National Natural Science Foundation of China(22078006);National Natural Science Foundation of China(22372022);Fundamental Research Funds for the Central Universities(DUT22LAB602)

摘要:

将CO2催化转化为燃料及高价值化学品, 被公认为是一条极具前景的技术路线, 有助于降低化石能源依赖并缓解CO2排放问题. 近年来, CO2加氢制备长链烃类(C2及以上)受到越来越多科研人员的关注. 目前, 该体系公认的反应机理为CO2基费托合成(CO2-FTS)路径: 即先经逆水煤气变换(RWGS)反应生成CO, 再通过经典FTS反应将CO转化为烃类产物. Fe基催化剂因成本低廉, 且在RWGS与FTS两步反应中均具备高催化活性, 在CO2基费托合成体系中展现出巨大应用潜力.
CO2直接加氢制备高附加值烯烃是极具应用前景的规模化CO2转化路线. 然而, 开发兼具高活性、高烯烃选择性与优异稳定性的催化剂仍存在诸多难题, 特别是在近工业实际工况下引入载体/粘结剂时该问题尤为突出. 合适的载体/粘结剂是提升活性位点稳定性和增强工业催化剂机械强度的关键, 对成型后的颗粒催化剂而言尤为重要. SiO2在工业Fe基费托合成催化剂中被广泛用作载体/粘结剂, 但将其用于CO2加氢催化剂体系时, 往往会造成反应性能大幅下降. 本文采用沉淀法制备了Zn改性Fe基催化剂, 定向调控Fe-Si间相互作用, 成功将硅溶胶(SiO2)用作CO2加氢Fe基催化剂的增效型载体/粘结剂, 而非抑制组分. 系统探究了Zn助剂对催化剂结构与反应性能的调控作用. 研究发现: 硅物种能够稳定催化剂中的碳化铁活性相. 因此, FeSi催化剂显示出优异的长效稳定性, 而不含硅物种的Fe和FeZn催化剂的活性持续下降. 然而, FeSi催化剂中存在较强的Fe-Si相互作用, 使活性相表面呈现缺电子状态, 改变CO中间体的吸附特性, 不利于长链产物和烯烃的生成. 通过引入Zn助剂, 用于调控含SiO2铁基催化剂中不利的Fe-Si相互作用. 改性后的FeZnSi催化剂在高空速条件下, 单程C2+烯烃收率最高可达0.6 g·gcat-1·h-1, 且可稳定运行500 h以上, 具备优异的操作稳定性. 多种表征结果结合理论计算研究证实: 在原位反应活化阶段, Zn会诱导生成Zn2SiO4物相来取代常规的Fe-O-Si键合结构, 削弱有害的强Fe-Si相互作用. 催化剂表面富含电子富集态χ-Fe5C2物相与大量表面氧空位, 有效强化了CO2与CO中间体的吸附活化能力, 共同赋予体系优异的催化活性与烯烃收率. 同时, Zn2SiO4物相则保障了催化剂长期稳定运行.
综上, 本文为CO2加氢催化体系中金属-载体/粘结剂相互作用的精准调控提供了重要理论依据, 尤其对成型工艺苛刻和长效稳定性要求高的工业级催化剂设计具有指导价值, 为开发可面向工业化应用的CO2加氢催化剂提供了新思路.

关键词: CO2加氢, 铁基催化剂, 烯烃, Fe-Si相互作用, 稳定性, 载体/粘结剂

Abstract:

The direct hydrogenation of CO2 to high-value olefins represents one of the most attractive pathways for large-scale CO2 conversion. However, developing catalysts that are active, selective, and stable for olefin production remains challenging, particularly when incorporating support or binder under industrially relevant conditions. Although silica (SiO2) is widely used as a support or binder in industrial Fe-based Fischer-Tropsch synthesis (FTS), its incorporation often leads to poor performance in CO2 hydrogenation. In this work, we introduce a Zn promoter to modulate the detrimental Fe-Si interaction in SiO2-containing Fe-based catalysts for CO2 hydrogenation. The resulting catalyst achieves a single-pass C2+ olefin yield as high as 0.6 g·gcat-1·h-1, coupled with exceptional operational stability for over 500 h at high space velocity. Multiple characterization techniques reveal that during the in-situ reaction-activation stage, Zn promotes the formation of a Zn2SiO4 phase, which alleviates the adverse Fe-O-Si interaction. The high content of χ-Fe5C2 with electron-enriched surface and abundant surface oxygen vacancies contribute to the outstanding catalytic activity and selectivity, while the presence of Zn2SiO4 contributes to long-term stability. These findings provide valuable insights for the rational regulation of metal-support/binder interactions in CO2 hydrogenation catalytic systems, especially for the design of catalysts where shaping processes and long-term durability pose significant challenges.

Key words: CO2 hydrogenation, Iron catalysts, Olefins, Fe-Si interaction, Stability, Support/binder