Sun Chunwen, Sun Jie, Xiao Guoliang, Zhang Huairuo, Qiu Xinping, Li Hong, Chen Liquan
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China.
J Phys Chem B. 2006 Jul 13;110(27):13445-52. doi: 10.1021/jp062179r.
Nearly monodisperse flowerlike CeO2 microspheres were synthesized via a simultaneous polymerization-precipitate reaction, metamorphic reconstruction, and mineralization under hydrothermal condition as well as subsequent calcination. The obtained CeO2 microsphere consists of 20-30 nm thick nanosheets as petals. It has an open three-dimensional (3D) porous and hollow structure and possesses high surface area, large pore volume, and marked hydrothermal stability. It can be doped easily after synthesis, and the initial 3D texture is maintained. The controlling factors and a possible formation mechanism are discussed in detail. This novel material can be used as a support for catalysts with various purposes. With CuO loaded on flowerlike CeO2, the catalytic activities and hydrothermal stability of Cu/CeO2 for ethanol stream reforming were examined. At 300 degrees C, the H2 selectivity reached a maximum value of 74.9 mol %, while CO was not detected within the precision of the gas chromatogram. It produced a hydrogen-rich gas mixture in the wide temperature range (300-500 degrees C) and showed excellent hydrothermal stability at high temperature (550 degrees C), which is a good choice for ethanol processors for hydrogen fuel cell applications.
通过水热条件下的同步聚合 - 沉淀反应、变质重构和矿化以及随后的煅烧，合成了近乎单分散的花状二氧化铈微球。所获得的二氧化铈微球由厚度为20 - 30nm的纳米片作为花瓣组成。它具有开放的三维（3D）多孔和中空结构，具有高比表面积、大孔体积和显著的水热稳定性。合成后易于掺杂，且能保持初始的3D结构。详细讨论了控制因素和可能的形成机制。这种新型材料可作为多种用途催化剂的载体。将氧化铜负载在花状二氧化铈上，考察了Cu/CeO₂对乙醇蒸汽重整的催化活性和水热稳定性。在300℃时，氢气选择性达到最大值74.9mol%，而在气相色谱精度范围内未检测到一氧化碳。它在宽温度范围（300 - 500℃）内产生富氢气体混合物，并且在高温（550℃）下表现出优异的水热稳定性，这对于用于氢燃料电池应用的乙醇处理器来说是一个不错的选择。
