Kosari Mohammadreza, Seayad Abdul Majeed, Xi Shibo, Kozlov Sergey M, Borgna Armando, Zeng Hua Chun
Department of Chemical and Biomolecular Engineering, Faculty of Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833.
ACS Appl Mater Interfaces. 2020 May 20;12(20):23060-23075. doi: 10.1021/acsami.0c03052. Epub 2020 May 11.
Hollow functional metal silicate materials have received the most interest due to their large inner space, permeable and functional shell, lighter density, and better use of material compared to their solid counterparts. While tremendous success has been made in the synthesis of individual metal silicates with uniform morphology, the synthesis of multiphase hollow silicates has not been explored yet, although their direct applications could be promising. In this study, mesoporous aluminosilicate spheres (MASS) are transformed to submicrometer copper aluminosilicate hollow spheres (CASHS) via a one-pot hydrothermal process. CASHS has a hollow interior with Cu-Al-Si thorn-like moieties in a lamellar structure on its outer shell. The structure and morphology of CASHS are unique and different from the previously reported tubular copper silicates that are emanated from Stöber silica spheres. Herein, we also demonstrate that the extent of hollowing in CASHS can be attained by controlling the aluminum content of pristine MASS, highlighting the existence of parameters for in situ controlling the shell thickness of hollow materials. The application of CASHS as a potential heterogeneous catalyst has been directed to important oxidation processes such as olefin oxidation and the advanced oxidation process (AOP). In cyclohexene oxidation, for instance, high selectivity to cyclohex-2-en-1-one is achieved under moderate conditions using -butyl hydroperoxide as the oxidant. CASHS is a robust heterogeneous catalyst and recyclable for this reaction. CASHS-derived catalysts also favor AOP and enhance the removal of cationic dyes together with HO through an adsorption-degradation process.
中空功能性金属硅酸盐材料因其较大的内部空间、可渗透的功能性外壳、较低的密度以及相较于实心材料更优的材料利用率而备受关注。尽管在合成具有均匀形态的单一金属硅酸盐方面已取得了巨大成功，但多相中空硅酸盐的合成尚未得到探索，尽管它们的直接应用前景广阔。在本研究中，介孔硅铝酸盐球（MASS）通过一锅水热法转化为亚微米级铜铝硅酸盐中空球（CASHS）。CASHS具有中空的内部结构，其外壳呈层状结构，带有Cu-Al-Si刺状部分。CASHS的结构和形态独特，与先前报道的由Stöber二氧化硅球衍生而来的管状铜硅酸盐不同。在此，我们还证明了通过控制原始MASS的铝含量可以实现CASHS的中空程度，这突出了原位控制中空材料壳厚度参数的存在。CASHS作为潜在的多相催化剂已应用于重要的氧化过程，如烯烃氧化和高级氧化过程（AOP）。例如，在环己烯氧化反应中，以叔丁基过氧化氢为氧化剂，在温和条件下对环己-2-烯-1-酮具有高选择性。CASHS是一种稳健的多相催化剂，可用于该反应的循环使用。由CASHS衍生的催化剂也有利于AOP，并通过吸附-降解过程增强与HO一起去除阳离子染料的能力。
