Gan Tao, Tao Lei, Zhang Zedong, Zhou Awu, Chen Yu, Li Jiong, Zhang Shuo, Du Shixuan, Li Yadong
Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China.
Department of Chemistry, Tsinghua University, Beijing 100084, China.
J Am Chem Soc. 2025 Sep 10;147(36):32729-32736. doi: 10.1021/jacs.5c08521. Epub 2025 Sep 1.
The inherent trade-off between activity and stability in platinum single-atom catalysts (SACs) poses a significant challenge for catalytic oxidation reactions. High-coordination Pt sites have good stability, but their overoxidation often passivates activity. In contrast, metastable low-coordination Pt structures typically display high activity but are prone to oxidation and aggregation under harsh conditions. Herein, we propose a defect-engineering strategy to address this dilemma by anchoring oxidized Pt single atoms onto vacancy LaFeO (v-LaFeO) perovskite. The introduced La-vacancy substantially reduces the oxygen vacancy formation energy of LaFeO, enhancing lattice oxygen mobility while preserving structural integrity. Pt single-atom sites with a high oxidation state (Pt) are anchored on the support, and their coordination environments are optimized. The catalyst exhibits high and stable activity for CO oxidation without reduction pretreatment. The structural characterization and in situ experiments indicate that vacancies in LaFeO positively regulate the electronic structure between the Pt and v-LaFeO interface. The longer Pt-O bonds activate interface oxygen species, accelerate O activation, and promote the cycling of CO oxidation. The oxidized Pt atoms and high coordination number enable its stability in long-term and high-temperature oxidation reactions. DFT calculations further verify the structure and reaction mechanism. This work demonstrates that precise control of support defects can concurrently optimize the electronic states and stability of SACs, offering a generalized paradigm for designing robust oxidation catalysts.
铂单原子催化剂（SACs）活性与稳定性之间固有的权衡对催化氧化反应构成了重大挑战。高配位的铂位点具有良好的稳定性，但其过度氧化往往会使活性钝化。相比之下，亚稳态的低配位铂结构通常表现出高活性，但在苛刻条件下容易发生氧化和聚集。在此，我们提出一种缺陷工程策略来解决这一困境，即将氧化的铂单原子锚定在空位型LaFeO（v-LaFeO）钙钛矿上。引入的镧空位大幅降低了LaFeO的氧空位形成能，提高了晶格氧迁移率，同时保持了结构完整性。具有高氧化态（Pt）的铂单原子位点锚定在载体上，其配位环境得到优化。该催化剂在无需还原预处理的情况下对CO氧化表现出高且稳定的活性。结构表征和原位实验表明，LaFeO中的空位正向调节Pt与v-LaFeO界面之间的电子结构。更长的Pt-O键激活了界面氧物种，加速了O的活化，并促进了CO氧化的循环。氧化的铂原子和高配位数使其在长期和高温氧化反应中具有稳定性。DFT计算进一步验证了结构和反应机理。这项工作表明，精确控制载体缺陷可以同时优化SACs的电子态和稳定性，为设计稳健的氧化催化剂提供了一种通用范式。
