Institute of Minerals and Materials Technology, C and MC Department, Bhubaneswar 751013, Orissa, India.
J Colloid Interface Sci. 2009 Dec 15;340(2):209-17. doi: 10.1016/j.jcis.2009.08.037. Epub 2009 Aug 31.
The Mobil Composition of Matter No. 41 (MCM-41) containing Cu and Al with Si/Al ratios varying from 100 to 10 and 1 to 6wt.% of Cu was synthesized under hydrothermal and impregnation conditions, respectively. The samples were characterized by nitrogen adsorption-desorption measurements, X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), temperature-programmed reduction (TPR), temperature-programmed desorption (TPD), and (29)Si and (27)Al magic-angle spinning-nuclear magnetic resonance (MAS-NMR) spectra. X-ray diffraction patterns indicate that the modified materials retain the standard MCM-41 structure. TPR patterns show the two-step reduction of Cu species. TPD study shows that Cu-impregnated Al-MCM-41 samples are more acidic than Al-MCM-41. From the MAS-NMR it was confirmed that most of the Al atoms are present tetrahedrally within the framework and some are present octahedrally in extraframework position. Impregnation of Cu shifted Al to the extraframework position. The catalytic activity of the samples toward hydroxylation of phenol in aqueous medium was evaluated using H(2)O(2) as the oxidant at 80 degrees C. The effects of reaction parameters such as temperature, catalyst amount, amount of H(2)O(2), and solvent were also investigated. Sample containing 4wt.% copper-loaded Al-MCM-41-100 showed high phenol conversion (78%) with 68% catechol and 32% hydroquinone selectivity.
Mobil Composition of Matter No. 41（MCM-41）含有 Cu 和 Al，Si/Al 比为 100-10 和 1-6wt.%的 Cu，分别在水热和浸渍条件下合成。样品通过氮气吸附-脱附测量、X 射线粉末衍射（XRD）、傅里叶变换红外光谱（FTIR）、紫外可见漫反射光谱（UV-Vis DRS）、程序升温还原（TPR）、程序升温脱附（TPD）和（29）Si 和（27）Al 魔角旋转-核磁共振（MAS-NMR）谱进行了表征。X 射线衍射图谱表明，改性材料保留了标准的 MCM-41 结构。TPR 图谱显示 Cu 物种的两步还原。TPD 研究表明，Cu 浸渍的 Al-MCM-41 样品比 Al-MCM-41 更酸性。从 MAS-NMR 可以证实，大多数 Al 原子以四面体形式存在于骨架中，有些以八面体形式存在于骨架外。Cu 的浸渍将 Al 转移到骨架外位置。在 80°C 下，以 H2O2 为氧化剂，在水相中评价了样品对苯酚羟化的催化活性。还研究了反应参数如温度、催化剂用量、H2O2 用量和溶剂的影响。含有 4wt.%负载铜的 Al-MCM-41-100 的样品显示出高的苯酚转化率（78%），具有 68%的邻苯二酚和 32%的对苯二酚选择性。
