Facile synthesis for ordered mesoporous gamma-aluminas with high thermal stability.
Facile synthesis for ordered mesoporous gamma-aluminas with high thermal stability.
复制标题
DOI：
10.1021/ja0764308
复制
发表时间：
2008-02
影响因子：
15
通讯作者：
Q. Yuan;An-Xiang Yin;C. Luo;Ling-Dong Sun;Ya‐Wen Zhang;Wentao Duan;Haichao Liu;Chunhua Yan
中科院分区：
文献类型：
--
作者：
Q. Yuan;An-Xiang Yin;C. Luo;Ling-Dong Sun;Ya‐Wen Zhang;Wentao Duan;Haichao Liu;Chunhua Yan
系统地研究了具有高热稳定性和孔径可调的高度有序介孔氧化铝的简易合成。一般的合成策略是基于与非离子嵌段共聚物作为模板剂在乙醇溶剂中的溶胶-凝胶过程。小角XRD、TEM和氮气吸附脱附结果表明，这些介孔氧化铝具有高度有序的二维六方介孔结构，耐高温可达1000 ℃。采用不同的前体、不同的酸作为pH调节剂、不同的嵌段共聚物作为模板，获得了孔径可调的有序介孔结构。这些介孔氧化铝具有大的表面积（约100 μ m）。400 m2/g）、孔体积（约. 0.70 cm 3/g）和窄的孔径分布。详细讨论了阴离子与羟基羧酸络合能力、酸挥发性等重要合成条件对合成的影响。利用这个简单的策略，我们也得到了部分有序的介孔氧化铝与水合硝酸铝为前体。FTIR吡啶吸附测试结果表明，介孔氧化铝中存在大量的刘易斯酸中心。这些材料具有均匀的孔结构、大的比表面积、可调的孔径和大量的表面刘易斯酸中心，有望成为催化剂的良好候选材料。以丙酮、D-葡萄糖和D-（+）-纤维二糖为催化剂，负载钌后的介孔氧化铝具有反应物尺寸选择性，在择形催化方面具有潜在的应用前景。
The facile synthesis of highly ordered mesoporous aluminas with high thermal stability and tunable pore sizes is systematically investigated. The general synthesis strategy is based on a sol-gel process associated with nonionic block copolymer as templates in ethanol solvent. Small-angle XRD, TEM, and nitrogen adsorption and desorption results show that these mesoporous aluminas possess a highly ordered 2D hexagonal mesostructure, which is resistant to high temperature up to 1000 degrees C. Ordered mesoporous structures with tunable pore sizes are obtained with various precursors, different acids as pH adjustors, and different block copolymers as templates. These mesoporous aluminas have large surface areas (ca. 400 m2/g), pore volumes (ca. 0.70 cm3/g), and narrow pore-size distributions. The influence of the complexation ability of anions and hydro-carboxylic acid, acid volatility, and other important synthesis conditions are discussed in detail. Utilizing this simple strategy, we also obtained partly ordered mesoporous alumina with hydrous aluminum nitrate as the precursor. FTIR pyridine adsorption measurements indicate that a large amount of Lewis acid sites exist in these mesoporous aluminas. These materials are expected to be good candidates in catalysis due to the uniform pore structures, large surface areas, tunable pore sizes, and large amounts of surface Lewis acid sites. Loaded with ruthenium, the representative mesoporous alumina exhibits reactant size selectivity in hydrogenation of acetone, D-glucose, and D-(+)-cellobiose as a test reaction, indicating the potential applications in shape-selective catalysis.