Inverse Oxide/Metal Catalysts in Fundamental Studies and Practical Applications: A Perspective of Recent Developments.

Inverse oxide/metal catalysts have shown to be excellent systems for studying the role of the oxide and oxide-metal interface in catalytic reactions. These systems can have special structural and catalytic properties due to strong oxide-metal interactions difficult to attain when depositing a metal on a regular oxide support. Oxide phases that are not seen or are metastable in a bulk oxide can become stable in an oxide/metal system opening the possibility for new chemical properties. Using these systems, it has been possible to explore fundamental properties of the metal-oxide interface (composition, structure, electronic state), which determine catalytic performance in the oxidation of CO, the water-gas shift and the hydrogenation of CO2 to methanol. Recently, there has been a significant advance in the preparation of oxide/metal catalysts for technical or industrial applications. One goal is to identify methods able to control in a precise way the size of the deposited oxide particles and their structure on the metal substrate.