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.
Chen, Y., Kasama, T., Huang, Z., Hu, P., Chen, J., Liu, X., & Tang, X. (2015). Highly Dense Isolated Metal Atom Catalytic Sites: Dynamic Formation and In Situ Observations. Chemistry-a European Journal, 21(48), 17397-17402. https://doi.org/10.1002/chem.201503068