Department of Chemical and Biomolecular Engineering, Faculty of Engineering, National University of Singapore , 10 Kent Ridge Crescent, Singapore 119260.
ACS Appl Mater Interfaces. 2017 Oct 25;9(42):37210-37218. doi: 10.1021/acsami.7b11808. Epub 2017 Oct 11.
Functional hollow materials have attracted extensive research attention due to their promising prospects for catalysis. Herein, we report an alternative synthesis of hierarchically hollow structured materials directly from core-shell structured templates, based on confined chemical reactions between the solid matter of a core and shell under hydrothermal conditions. More specifically, we have developed a novel and facile strategy to transform core-shell structured CuO@mSiO (m = mesoporous) to tubular copper silicate assemblages (TCSA). Depending on the original shapes of CuO, TCSA can be tailored as spherical or cubic assemblages with stacking copper silicate nanotubes (inner diameter: 4.5 nm, thickness: 0.8 nm, length: ca. 96 nm) in the shell. Moreover, by utilizing the residual reductive Cu(I) (ca. 10 at% of total surface copper) on TCSA support, in situ generations of Pd nanoparticles (∼4.5 nm) and Au nanoparticles (∼5.8 nm) were successfully achieved based on the spontaneous galvanic replacement reactions. Two integrated nanocatalysts (viz., Pd/TCSA and Au/TCSA) have been prepared with this approach. As an example, Pd/TCSA exhibits excellent activity and recyclability for Suzuki-Miyaura cross-coupling reactions.
功能中空材料由于在催化方面的广阔前景而引起了广泛的研究关注。在此，我们报告了一种通过在水热条件下限制核心和壳之间的固体物质之间的化学反应，直接从核壳结构模板合成分级中空结构材料的替代方法。更具体地说，我们开发了一种新颖且简便的策略，可将核壳结构的 CuO@mSiO（m = 介孔）转化为管状硅酸铜组装体（TCSA）。根据 CuO 的原始形状，TCSA 可以被定制为具有堆叠硅酸铜纳米管（内径：4.5nm，厚度：0.8nm，长度：约 96nm）的球形或立方组装体。此外，通过利用 TCSA 载体上残留的还原 Cu(I)（约占总表面铜的 10at%），可以基于自发的电置换反应成功原位生成 Pd 纳米颗粒（约 4.5nm）和 Au 纳米颗粒（约 5.8nm）。使用这种方法制备了两种集成的纳米催化剂（即 Pd/TCSA 和 Au/TCSA）。例如，Pd/TCSA 在 Suzuki-Miyaura 偶联反应中表现出优异的活性和可回收性。
