State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. wangca@mail. tsinghua.edu.cn.
Nanoscale. 2019 Apr 4;11(14):6776-6783. doi: 10.1039/c9nr01737b.
The development of strategies for the facile fabrication of noble metal/metal oxide nanomaterials with high catalytic activity and thermal stability is very challenging in the field of catalysis and for other relevant applications. Herein, we report a delicate multi-assembly method to prepare sandwich-like MnO2-Pd-CeO2 hollow spheres wherein carbon spheres were employed as sacrificial templates. Typically, tiny Pd nanoparticles were deposited on the outer surface of the MnO2 shell, and the CeO2 overcoating served as a nanotrap to anchor the Pd particles on the MnO2 supports. The unique sandwich-like structure effectively prevents the Pd nanoparticles from aggregation during high-temperature calcination and catalyzation. The as-prepared MnO2-Pd-CeO2 hollow spheres exhibited enhanced stability and activity for CO oxidation. The excellent stability and activity exhibited by the as-synthesized MnO2-Pd-CeO2 hollow spheres can be ascribed to the sandwich-like structure and the strong synergistic effects between Pd and the hierarchical porous MnO2-CeO2 shell. We believe that this optimal structure design demonstrates a new approach for the synthesis of noble-metal-based catalysts with superior activity and stability.
在催化及其他相关应用领域，开发简便的方法来制备具有高催化活性和热稳定性的贵金属/金属氧化物纳米材料的策略极具挑战性。在此，我们报告了一种巧妙的多组装方法，制备三明治状的 MnO2-Pd-CeO2 空心球，其中碳球被用作牺牲模板。通常，微小的 Pd 纳米颗粒沉积在 MnO2 壳的外表面上，CeO2 覆盖层作为纳米阱将 Pd 颗粒锚定在 MnO2 载体上。独特的三明治状结构可有效防止 Pd 纳米颗粒在高温煅烧和催化过程中聚集。所制备的 MnO2-Pd-CeO2 空心球在 CO 氧化反应中表现出增强的稳定性和活性。所合成的 MnO2-Pd-CeO2 空心球表现出的优异稳定性和活性可归因于三明治状结构以及 Pd 和分级多孔 MnO2-CeO2 壳之间的强协同作用。我们相信，这种最佳结构设计为具有优异活性和稳定性的贵金属基催化剂的合成提供了一种新方法。
