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首页> 外文期刊>Journal of Colloid and Interface Science >Evaporation-induced self-assembly synthesis of nanostructured alumina-based mixed metal oxides with tailored porosity
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Evaporation-induced self-assembly synthesis of nanostructured alumina-based mixed metal oxides with tailored porosity

机译：蒸发诱导的纳米结构氧化铝的混合金属氧化物的自组装合成，具有量身定制的孔隙率

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The one-pot synthesis of nanostructured ternary mixed oxides is challenging due to the heterogeneous nature of the hydrolysis and condensation processes of all metal oxide precursors. In addition, the solvents and additives used can affect these processes too. Herein, we report the effect of different solvents (ethanol, 1- and 2-propanol, or butanol) and additives (citric acid or 1,3,5-triisopropylbenzene) used on the formation of binary and ternary alumina-based oxides, NiO-Al2O3, NiO-TiO2-Al2O3, and NiO-ZrO2-Al2O3 in the presence of triblock copolymer Pluronic P123 used as a soft template. For comparison, this study includes also mesoporous Al2O3 prepared at the same conditions. It is shown that the kinetics of hydrolysis and condensation processes of metal alkoxides, and consequently, the properties of the resulting alumina-based mixed metal oxides are controllable by varying the solvents used. The use of propanol instead of ethanol affords mixed metal oxides with improved degree of mesostructure uniformity as evidenced by narrower pore size distributions. This finding is attributed to the smaller exchange of propanol with propoxide groups in Al(OPri)(3), Ti(OPri)(4), and Zr(OPrn)(4) which results in an enhanced stability of the formed mesophase. Furthermore, the addition of citric acid leads to smaller pore sizes without significant changes in the textural properties of metal oxides, while addition of 1,3,5-triisopropylbenzene affords oxides with enlarged pores. The mixed metal oxides studied feature large specific surface areas (310-460 m(2).g(-1)), large pore volumes (0.5-0.75.cm(3).g(-1)), and uniform mesopores with widths ranging from 5 to 18 nm. Solid-state kinetic studies performed by thermal analysis using both isoconversional and model fitting methods reveal the complexity of the mesophase formation. The thermal decomposition of condensed oxoalkoxide species into metal oxides is mainly diffusion-controlled and affected by the type of solvent used too. Th
机译：由于所有金属氧化物前体的水解和缩合过程的异质性质，纳米结构三元混合氧化物的单罐合成是挑战。此外，所用溶剂和添加剂也会影响这些过程。在此，我们报告了不同溶剂（乙醇，1-和2-丙醇，或丁醇）和添加剂（柠檬酸或1,3,5-三异丙基苯）的作用，用于形成二元和三元氧化氮基氧化物的形成，NIO -A12O3，NiO-TiO2-Al 2 O 3和NiO-ZrO2-Al 2O3在存在三嵌段共聚物Pluronic P123中用作软模板。为了比较，该研究还包括在相同条件下制备的中孔Al2O3。结果表明，金属醇盐的水解和缩合过程的动力学，因此，通过改变所用溶剂来控制所得氧化铝基混合金属氧化物的性质。使用丙醇代替乙醇提供混合金属氧化物，其具有较高的型材结构均匀程度，如较窄的孔径分布所证明。该发现归因于丙酮与丙酮丙醇中的丙醇在Al（OPRI）（3），Ti（OPRI）（4）和Zr（OPRN）（4）中的较低交换，这导致形成的中间相的增强稳定性。此外，在金属氧化物的纹理性质的情况下，加入柠檬酸导致较小的孔径尺寸，同时加入1,3,5-三异丙基苯，孔隙率和扩大的孔。研究的混合金属氧化物具有大的比表面积（310-460m（2）.g（-1）），大孔体积（0.5-0.75.cm（3）.g（-1））和均匀的中孔宽度范围为5至18 nm。通过使用异组谐波和模型配件方法进行热分析进行的固态动力学研究揭示了中间相形成的复杂性。将浓缩的氧氧化物物种的热分解成金属氧化物主要是扩散控制和受溶剂类型的影响。 TH.

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