Highly Dense Isolated Metal Atom Catalytic Sites: Dynamic Formation and In Situ Observations

作者：Chen, Yaxin; Kasama, Takeshi; Huang, Zhiwei; Hu, Pingping; Chen, Jianmin; Liu, Xi^*; Tang, Xingfu

来源：Chemistry - A European Journal, 2015, 21(48): 17397-17402.

DOI：10.1002/chem.201503068

• electron microscopy
• heterogeneous catalysis
• surface analysis
• surface chemistry
• X-ray diffraction

Atomically dispersed noble-metal catalysts with highly dense active sites are promising materials with which to maximise metal efficiency and to enhance catalytic performance; however, their fabrication remains challenging because metal atoms are prone to sintering, especially at a high metal loading. A dynamic process of formation of isolated metal atom catalytic sites on the surface of the support, which was achieved starting from silver nanoparticles by using a thermal surface-mediated diffusion method, was observed directly by using in situ electron microscopy and in situ synchrotron X-ray diffraction. A combination of electron microscopy images with X-ray absorption spectra demonstrated that the silver atoms were anchored on five-fold oxygen-terminated cavities on the surface of the support to form highly dense isolated metal active sites, leading to excellent reactivity in catalytic oxidation at low temperature. This work provides a general strategy for designing atomically dispersed noble-metal catalysts with highly dense active sites.

• 出版日期2015-11-23
• 单位复旦大学