| Structural Evolvement of Heating Treatment of Mg/AI-LDH and Preparation of Mineral Mesoporous Materials |
| |
| 作者姓名： | CHEN Tianhu XU Huifang WANG Yifeng QING Chengsong FAN Mingde CHEN Gang |
| |
| 作者单位： | [1]School of Natural Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China [2]Department of Geology and Geophysics, University of Wisconsin, Madison, WI 53706, USA [3]Sandia National Laboratories, P.O. Box 58 |
| |
| 基金项目： | This research is part of a project carried out during 2004-2005 and was financially supported by the National Natural Science Foundation of China （No. 40472026） and the 0utstanding 0verseas Chinese Scholars Fund of Chinese Academy of Sciences （2003-1-7）. |
| |
| 摘 要： | Although hydrotalcite, or layered double hydroxides （LDHs）, is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/AI-LDH is evaluated by XRD, TEM and N2-BET analyses. The results indicate that the magnesium-aluminum LDH with carbonate as interlayer anion, periclase-like oxides was formed at temperatures of 400-800℃. Meanwhile, 2-3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase-like formed from LDH heat treatment may re-hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of （Mg, Al）-oxide nano-crystals and nanopores among the nano-crystals. When heating temperature exceeds 1000, the periclase-like （Mg, Al）-oxide is transformed into a composite with periclase （MgO） and spinel phases. The periclase can be re-hydrolyzed and dissolved in HCl solution. After acid treatment, the sample with a high surface area is composed of spinel nano-crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition.
|
| 关 键 词： | 水滑石 氢氧化物 热处理 矿物结构 |
| 收稿时间： | 2005-07-20 |
| 修稿时间： | 2005-12-01 |
Structural Evolvement of Heating Treatment of Mg/AI-LDH and Preparation of Mineral Mesoporous Materials |
| |
| Authors: | CHEN;Tianhu;XU;Huifang;WANG;Yifeng;QING;Chengsong;FAN;Mingde;CHEN;Gang |
| |
| Abstract: | Abstract Although hydrotalcite, or layered double hydroxides (LDHs), is not a common mineral, it is an important material that can be easily synthesized in laboratory. In this study, structural evolvement and BET surface area changes of heat treated Mg/Al‐LDH is evaluated by XRD, TEM and N2‐BET analyses. The results indicate that the magnesium‐aluminum LDH with carbonate as interlayer anion, periclase‐like oxides was formed at temperatures of 400–800°C. Meanwhile, 2–3 nanometer mesoporous were formed during decomposition of LDH. However, the heat treated samples still preserve the morphology of the original LDH plates. Periclase‐like formed from LDH heat treatment may re‐hydrolyze and recover the structure of LDH. However, crystallinity of the recovered LDH is lower than that of the original LDH. This heat treatment will result in formation of (Mg, Al)‐oxide nano‐crystals and nanopores among the nano‐crystals. When heating temperature exceeds 1000, the periclase‐like (Mg, Al)‐oxide is transformed into a composite with periclase (MgO) and spinel phases. The periclase can be re‐hydrolyzed and dissolved in HCI solution. After acid treatment, the sample with a high surface area is composed of spinel nano‐crystals and nanopores among them. Our results will provide a new and economic way to synthesize mesoporous materials through pathways of phase transformation of precursor materials with different composition. |
| |
| Keywords: | hydrotalcite layered double hydroxides mesoporous materials |
| 本文献已被 维普 等数据库收录！ |
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |
|
