Kim Sang Woo, Kim Inho, Moon Dong Ju
Clean Energy Research Center, Korea Institute of Science and Technology, 39-1 Haweolgok-Dong, Korea.
J Nanosci Nanotechnol. 2013 Aug;13(8):5750-3. doi: 10.1166/jnn.2013.7038.
Nanostructured magnesium oxide catalyst support materials with controlled morphology and size were synthesized from a supercritical carbon dioxide/ethanol solution via chemical reaction of soluble precursors and subsequent thermal decomposition. Leaf-like magnesium hydroxide precursors with high specific surface area were formed by a low-temperature chemical reaction at below 140 degrees C, while magnesium carbonate cubes with a very low surface area less than 3.3 m2/g were formed by temperature-induced phase transition from a loose to a dense structure during carbonation reaction at above 150 degrees C. The specific surface area has significantly increased higher than 90 m2/g due to the creation of highly porous MgO cubes with mesopore structure formed after thermal decomposition of the magnesium carbonate precursors. Ni-magnesium oxide catalysts with bimodal pore structure were finally formed by the consequence of packing heterogeneity of the porous magnesium oxides with different morphologies and sizes.
通过可溶性前驱体的化学反应及随后的热分解，从超临界二氧化碳/乙醇溶液中合成了具有可控形态和尺寸的纳米结构氧化镁催化剂载体材料。通过在140℃以下的低温化学反应形成了具有高比表面积的叶状氢氧化镁前驱体，而在150℃以上的碳酸化反应过程中，通过温度诱导的从松散结构到致密结构的相变，形成了比表面积极低（小于3.3m²/g）的碳酸镁立方体。由于碳酸镁前驱体热分解后形成了具有介孔结构的高度多孔氧化镁立方体，比表面积显著增加，高于90m²/g。最终，由于不同形态和尺寸的多孔氧化镁堆积不均匀，形成了具有双峰孔结构的镍-氧化镁催化剂。
