催化学报 ›› 2024, Vol. 61: 259-268.DOI: 10.1016/S1872-2067(24)60048-3

• 论文 • 上一篇    下一篇

金属镍活性中心在惰性金属载体中的自分散及其催化炔烃选择加氢性能

邓欣a, 郑彩艳b, 李玮杰a, 王佳敏a, 杨迪a, 胡振芃b, 李兰冬a,c,*()   

  1. a南开大学化学学院, 有机新物质创造前沿科学中心, 天津 300071
    b南开大学物理科学学院, 天津 300071
    c物质绿色创造与制造海河实验室, 天津 300192
  • 收稿日期:2024-02-22 接受日期:2024-04-29 出版日期:2024-06-18 发布日期:2024-06-20
  • 通讯作者: * 电子信箱: lild@nankai.edu.cn (李兰冬).
  • 基金资助:
    国家自然科学基金(22121005);国家自然科学基金(22302099);国家自然科学基金(22025203);中国博士后科学基金(2023M731797)

Spontaneous dispersion of metallic nickel centers in inert metal substrate for the selective hydrogenation of carbon-carbon triple bonds

Xin Denga, Caiyan Zhengb, Weijie Lia, Jiamin Wanga, Di Yanga, Zhenpeng Hub, Landong Lia,c,*()   

  1. aFrontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300371, China
    bSchool of Physics, Nankai University, Tianjin 300071, China
    cHaihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
  • Received:2024-02-22 Accepted:2024-04-29 Online:2024-06-18 Published:2024-06-20
  • Contact: * E-mail: lild@nankai.edu.cn (L. Li).
  • Supported by:
    National Natural Science Foundation of China(22121005);National Natural Science Foundation of China(22302099);National Natural Science Foundation of China(22025203);China Postdoctoral Science Foundation(2023M731797)

摘要:

单位点催化剂因具有较好的活性、较高的原子利用率和目标产物选择性, 在基础科学研究及工业生产领域受到了广泛关注. 然而, 单位点催化剂的合成策略通常较为繁琐, 需要精细调控金属活性中心与载体之间的相互作用. 较弱的相互作用可能会导致金属活性位点的迁移和聚集, 形成金属团簇, 进而引发不必要的副反应. 另一方面, 过分紧密的相互作用可能会限制金属活性位点的原子效率, 从而降低反应活性.
本文开发了一种简单通用的自分散策略, 用于制备金属态单位点催化剂. 该方法利用过渡金属活性中心镍在惰性载体(铝和镁)中的自分散行为, 成功构筑了含有孤立过渡金属镍活性中心的全金属催化体系. X射线光电子能谱、低能离子散射和球差矫正扫描透射电子显微镜等表征结果证实了镍/铝催化剂中镍物种以金属态存在, 且以孤立状态均匀分布于铝基载体的亚表层. 在气固相乙炔选择加氢反应中, 镍/铝和镍/镁催化剂表现出较好的催化性能, 能够实现100%的乙炔转化率和高乙烯选择性. 值得注意的是, 镍/铝催化剂在碳碳三键选择加氢反应中的催化性能甚至超越了工业界广泛使用的林德拉催化剂. 稳定性测试结果表明, 镍/铝催化剂在长达90 h的连续反应中, 能够维持稳定的乙炔转化率和乙烯选择性, 没有明显的活性下降, 进一步印证了其在工业应用中的潜在价值. 结合动力学分析、原位红外光谱、氢-氘-乙炔脉冲响应实验以及理论计算等结果, 详细阐释了镍/铝催化体系上乙炔选择加氢的反应机制. 结果表明, 氢气分子优先在镍/铝催化剂表面吸附并发生解离, 生成氢原子, 随后与乙炔分子逐步反应生成乙烯. 在该过程中, 氢气的解离活化是整个反应过程的决速步. 此外, 还进一步探讨了镍/铝催化体系对液相炔烃、炔醇选择加氢的性能, 发现该催化剂可以在较为温和的条件下高效催化不同官能团修饰的炔烃、炔醇的选择加氢反应, 同时保持高底物转化率和较好的烯烃、烯醇选择性, 且表现出较好的循环稳定性.
综上所述, 本文发展了一种全金属单位点催化体系的通用构筑策略, 不仅扩展了单位点金属催化体系的合成方法, 同时利用全金属体系的本征优势, 为化学转化反应过程提供了新的思路. 上述发现为设计合成新型高效催化体系提供了重要的理论和实验依据, 有望在精细化学品合成工业中得到应用.

关键词: 单位点, 全金属催化剂, 选择加氢, Ni基催化剂, 自分散

Abstract:

Single-site metal catalysts with maximal utilization of active centers and desired target product selectivity represent a hot research topic within the realms of both academic and industry. However, the synthetic strategy is generally complicated and requires the precise control of interplay between metal centers and supporting materials. Herein, a simple spontaneous dispersion and universal strategy are developed to construct all-metal catalyst systems containing isolated metallic centers utilizing the spontaneous dispersion behaviors of transition metal centers Ni in inert substrate (Al, Mg and Ti). Ni/Al and Ni/Mg show remarkable performances in the model reaction of acetylene semi-hydrogenation with state-of-the-art site-specific activity, high ethylene selectivity and good stability. Especially, Ni/Al is reported for the first time to be an eligible low-cost catalyst for the selective hydrogenation of carbon-carbon triple bonds, surpassing the benchmark Lindlar catalyst. The reaction mechanism of acetylene semi-hydrogenation over Ni/Al catalyst is well clarified via the combination of kinetic analyses, spectroscopy investigation and theoretical calculations. The innovative approach developed herein not only expands the synthetic strategies toward single-site metal catalysts but also holds promise for practical applications in diverse chemical transformations due to the intrinsic advantages of all-metal systems.

Key words: Isolated metallic site, All-metal catalyst, Selective hydrogenation, Ni-based catalyst, Spontaneous dispersion