Novel inverse oxide/metal catalysts for methanol synthesis: impact of oxide–metal interactions and reversible morphological changes

Inverse oxide/metal catalysts have proved to be excellent systems for the generation of methanol by CO₂hydrogenation or the partial oxidation of methane. These systems can exhibit unique structural and chemical properties due to the nano size of the oxide component and strong oxide-metal interactions. Recent studies for ZnO/Cu, CeO₂/Cu, TiO_2/Cu, MgO/Cu, In₂O₃/Cu, and In₂O₃/Au catalysts have shown large variations in the composition and morphology of the oxide overlayer as a function of temperature and chemical environment. These oxide-metal interfaces are able to react with CO₂and CH₄at room temperature, and both reactants have a strong influence on the physical and chemical properties of the catalysts. Under reaction conditions, switches between oxide-metal and metal-metal interfaces can take in the catalyst surface. A dynamic behavior that can be linked to a high selectivity for methanol production over systems such as ZnO/Cu, CeO₂/Cu and In₂O₃/Au. This type of correlation deserves additional systematic studies since it could be a powerful tool for designing highly efficient catalysts for methanol synthesis.