Jiang Luozhen, Tian Chen, Li Yunan, Si Rui, Du Meng, Li Xiuhong, Guo Lingling, Li Lina
Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.
Nanomaterials (Basel). 2022 Jul 5;12(13):2306. doi: 10.3390/nano12132306.
Morphology of support is of fundamental significance to the fabrication of highly efficient catalysts for CO oxidation reaction. Many methods for the construction of supports with specific morphology and structures greatly rely on controlling general physical and chemical synthesis conditions such as temperature or pH. In this paper, we report a facile route to prepare yttria nanosheet using NaCl as template to support platinum nanoparticles exhibiting higher CO oxidation activity than that of the normally prepared Pt/YO. With the help of TEM and SEM, we found that Pt NPs evenly distributed on the surface of NaCl modified 2D-nanosheets with smaller size. The combination of XAFS and TEM characterizations demonstrated that the nano-size Pt species with PtO structure played an essential role in the conversion of CO and kept steady during the CO oxidation process. Moreover, the Pt nanoparticles supported on the NaCl templated YO nanosheets could be more easily reduced and thus exposed more Pt sites to adsorb CO molecules for CO oxidation according to XPS and DRIFTS results. This work offers a unique and general method for the preparation of potential non-cerium oxide rare earth element oxide supported nanocatalysts.
载体的形态对于制备用于CO氧化反应的高效催化剂具有至关重要的意义。许多构建具有特定形态和结构的载体的方法在很大程度上依赖于控制诸如温度或pH等一般物理和化学合成条件。在本文中，我们报道了一种简便的方法，以NaCl为模板制备氧化钇纳米片，用于负载铂纳米颗粒，该铂纳米颗粒表现出比常规制备的Pt/YO更高的CO氧化活性。借助透射电子显微镜（TEM）和扫描电子显微镜（SEM），我们发现铂纳米颗粒均匀分布在经NaCl修饰的二维纳米片表面，且尺寸更小。X射线吸收精细结构（XAFS）和TEM表征的结合表明，具有PtO结构的纳米尺寸铂物种在CO转化中起关键作用，并且在CO氧化过程中保持稳定。此外，根据X射线光电子能谱（XPS）和漫反射红外傅里叶变换光谱（DRIFTS）结果，负载在以NaCl为模板的YO纳米片上的铂纳米颗粒更容易被还原，从而暴露出更多的铂位点来吸附CO分子以进行CO氧化。这项工作为制备潜在的非氧化铈稀土元素氧化物负载型纳米催化剂提供了一种独特且通用的方法。
