Jang Hee Jin, Lee Chan Hyun, Kim Suji, Kim Sung Hyun, Lee Ki Bong
Department of Chemical and Biological Engineering, Korea University , 145 Anam-ro, Seongbuk-gu, Seoul 136-713, Republic of Korea.
ACS Appl Mater Interfaces. 2014 May 14;6(9):6914-9. doi: 10.1021/am500720f. Epub 2014 May 1.
In many materials for CO2 sorption, hydrotalcite is attracting substantial attention as a high temperature (200-500 °C) CO2 sorbent because of its fast sorption/desorption kinetics and easy regenerability. However, the CO2-sorption capacity of conventional hydrotalcite is relatively low for large-scale commercial use. To enhance CO2-sorption capacity, hydrotalcite is conventionally impregnated with alkali metals such as K2CO3. Although K2CO3-impregnated hydrotalcite has high CO2-sorption capacity, the preparation method takes long time and is inconvenient because hydrotalcite synthesis step and alkali metal impregnation step are separated. In this study, K2CO3-promoted hydrotalcite was newly synthesized from hydroxide-form percursors by a simple and eco-friendly method without a solvent-consuming washing step. Analysis based on X-ray diffraction indicated that the prepared samples had structures of well-defined hydrotalcite crystalline and un-reacted Mg(OH)2 precursor. Moreover, K2CO3 was successfully incorporated in hydrotalcite during the synthesis step. The prepared K2CO3-promoted hydrotalcite showed high CO2-sorption capacity and had potential for use as a high-temperature CO2 sorbent.
在许多用于二氧化碳吸附的材料中，水滑石作为一种高温（200 - 500°C）二氧化碳吸附剂正吸引着大量关注，这是因为其具有快速的吸附/解吸动力学以及易于再生的特性。然而，传统水滑石的二氧化碳吸附容量对于大规模商业应用来说相对较低。为了提高二氧化碳吸附容量，传统方法是用水滑石浸渍碱金属，如碳酸钾。尽管浸渍了碳酸钾的水滑石具有较高的二氧化碳吸附容量，但制备方法耗时较长且不方便，因为水滑石合成步骤和碱金属浸渍步骤是分开的。在本研究中，通过一种简单且环保的方法，从氢氧化物形式的前驱体中成功合成了碳酸钾促进的水滑石，且无需消耗溶剂的洗涤步骤。基于X射线衍射的分析表明，所制备的样品具有结构明确的水滑石晶体和未反应的氢氧化镁前驱体结构。此外，在合成步骤中碳酸钾成功地掺入了水滑石中。所制备的碳酸钾促进的水滑石表现出高二氧化碳吸附容量，具有作为高温二氧化碳吸附剂使用的潜力。
