Facile one-step synthesis of porous ceria hollow nanospheres for low temperature CO oxidation
Facile one-step synthesis of porous ceria hollow nanospheres for low temperature CO oxidation
复制标题
DOI：
10.1016/j.micromeso.2013.03.031
复制
发表时间：
2013-08
影响因子：
5.2
通讯作者：
Y. Jiao;Feifei Wang;Xiaoming Ma;Qinghu Tang;Kui Wang;Yuming Guo;Lin Yang
中科院分区：
文献类型：
--
作者：
Y. Jiao;Feifei Wang;Xiaoming Ma;Qinghu Tang;Kui Wang;Yuming Guo;Lin Yang
在此，多孔二氧化铈（CeO 2）的空心纳米球组成的小纳米粒子已经可控地通过一个简单的一步溶剂热反应，而不使用任何硬模板制备。采用X射线粉末衍射（XRD）、高分辨透射电子显微镜（HRTEM）、热重分析（TGA）、傅立叶变换红外光谱（FTIR）、场发射扫描电子显微镜（FESEM）和N2吸附/脱附分析对产物进行了表征。结果表明，多孔CeO 2空心纳米球由平均粒径为3 nm的小颗粒组成，粒径均匀，为135 nm，比表面积为145 m2/g。基于一系列随时间变化的高分辨透射电镜观察，提出了一种自组装过程与Ostwald熟化机制相结合的中空结构形成机制。考察了多孔CeO 2空心纳米球和Au/CeO 2复合催化剂对CO氧化的催化性能。结果表明，多孔CeO 2纳米空心球是Au纳米粒子的良好载体，室温下Au/CeO 2-A复合催化剂的CO转化率为92%。更重要的是，该催化剂在室温下连续使用20 h后，CO的转化率仍能达到91%，表明该催化剂具有较高的催化活性和耐久性。
Herein, porous ceria (CeO2) hollow nanospheres composed of small nanoparticles have been controllably prepared through a simple one-step solvothermal reaction without using any hard-template. The products were characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and N2adsorption/desorption analysis. It was found that the porous CeO2hollow nanospheres composed of small nanoparticles with an average diameter of 3nm have a uniform size of 135nm and a high specific surface area of 145m2/g. A self-assembly process coupled with an Ostwald ripening mechanism for the hollow structures formation was proposed based on a series of time-dependent HRTEM observations. The catalytic performance of porous CeO2hollow nanospheres and the Au/CeO2composite catalyst for CO oxidation were also tested. The results indicate that these porous CeO2hollow nanospheres are excellent supports for Au nanoparticles, the CO conversion by catalysis of Au/CeO2-A composite catalyst is 92% at ambient temperature. More importantly, the CO conversion could still be reached to 91% after the catalyst had been continuously used for 20h in CO oxidation at room temperature, indicating that the Au/CeO2-A catalyst had a high catalytic activity and high durability.