Real‐space observation of strong metal‐support interaction: state‐of‐the‐art and what's the next

• Published in: Journal of microscopy (Oxford) 2016-06, Vol.262 (3), p.203-215
• Main Authors: SHI, X.Y., ZHANG, W., ZHANG, C., ZHENG, W.T., CHEN, H., Qi, J.G.
• Format: Article
• Language: English
• Subjects: Atomic resolution; Catalysis; metal/oxide catalyst; strong metal‐support interaction (SMSI); surface analysis; Transmission electron microscopy
• ISSN: 0022-2720; 1365-2818
• DOI: 10.1111/jmi.12366

Summary The real‐space resolving of the encapsulated overlayer in the well‐known model and industry catalysts, ascribed to the advent of dedicated transmission electron microscopy, enables us to probe novel nano/micro architecture chemistry for better application, revisiting our understanding of this key issue in heterogeneous catalysis. In this review, we summarize the latest progress of real‐space observation of SMSI in several well‐known systems mainly covered from the metal catalysts (mostly Pt) supported by the TiO2, CeO2 and Fe3O4. As a comparison with the model catalyst Pt/Fe3O4, the industrial catalyst Cu/ZnO is also listed, followed with the suggested ongoing directions in the field. Lay description Strong metal‐support interaction (SMSI) is an important issue in catalysis, which can modify the catalytic properties of the well‐known metal/support systems. Besides maintaining metal particle size, SMSI can lead to, under a reduction condition at high temperature, the appearance of a sub‐oxide thin layer onto the metal nanoparticles in a metal/oxide catalyst. This kind of interaction between the metal and support is usually induced by the electron transferring from support to metal. The overlayer is correlated closely with the catalytic performance, such as activity and selectivity. Although the SMSI has been widely investigated by surface science methods, the advanced transmission electron microscopy (TEM) can directly confirm the existence of the oxide thin layer on the metal and unravel its effect on catalysis. In this review, we summarize some examples of SMSI, mainly focused on the thin layer occurred onto the surface of Pt supported by TiO2, CeO2 and Fe3O4 systems; the TEM investigation of the industrial catalyst Cu/ZnO is also listed.