Influence of microwave radiation on the textural properties of layered double hydroxides
Influence of microwave radiation on the textural properties of layered double hydroxides
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DOI：
10.1016/j.micromeso.2006.03.038
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发表时间：
2006-09-08
影响因子：
5.2
通讯作者：
Rives, V.
中科院分区：
文献类型：
--
作者：
Benito, P.;LabajoS, F. M.;Rives, V.
采用微波和常规水热法制备了Mg，Al-CO3和Mg，Cr-CO3两种层状双氢氧化物（LDHs），研究了微波辐射对其理化性质的影响。老化温度均为125℃。通过元素化学分析、粉末x射线衍射、差热分析和热重分析、Al-27 MAS NMR、FT-IR和UV-Vis漫反射光谱，以及-196℃下N-2吸附比表面积和孔隙度评估，对样品进行了全面表征。在所有情况下，唯一的结晶相是水滑石，微波水热处理比常规水热处理结晶度进一步提高。与常规热液老化相比，微波老化样品具有更大的层间水含量和更小的粒径。在老化处理过程中，固体的结构特性发生了强烈的变化，并且在微波辐射下的样品在较短的时间内观察到较大的比表面积值。(c) 2006爱思唯尔公司版权所有。
Two series of layered double hydroxides (LDHs) with compositions Mg,Al-CO3 and Mg,Cr-CO3 were prepared by microwave and conventional hydrothermal treatment to study the role of microwave radiation on their physicochemical properties. Aging temperature was 125 degrees C in all cases. The samples were fully characterised by element chemical analysis, powder X-ray diffraction, differential thermal analysis and thermogravimetric analysis, Al-27 MAS NMR, FT-IR and UV-Vis diffuse reflectance spectroscopies, and specific surface area and porosity assessment by N-2 adsorption at -196 degrees C. In all cases, the only crystalline phase obtained was hydrotalcite which crystallinity is further enhanced by microwave hydrothermal treatment than by conventional hydrothermal treatment. The microwave-aged samples also have larger amounts of interlayer water and smaller particle size than those prepared by conventional hydrothermal ageing. The textural properties of the solids are strongly modified during the ageing treatment, and large specific surface areas values are observed at shorter times for those samples subjected to microwave radiation. (c) 2006 Elsevier Inc. All rights reserved.