Approaches for Understanding and Controlling Interfacial Effects in Oxide-Supported Metal Catalysts

Heterogeneous supported metal catalysts are critical for a wide range of chemical conversion technologies. While the fundamental properties of extended metal surfaces are well understood and active sites on such systems can be designed for targeted applications, much less is known about the properties of active sites formed at the interface of nanometer-scale metal structures and their underlying oxide support. The goal of this Perspective is to highlight recent progress in understanding and controlling metal-oxide support interfacial sites on high-surface-area catalysts. Focus is given to how metal particle size, support migration onto metal particles, and intentional deposition of oxides on metal particles can be used to create high concentrations of interfacial sites. The impact of interface formation on properties of nearby metal and oxide sites is discussed in the context of understanding if the uniqueness of interfacial sites stems from bifunctionality, or if the distinct electronic properties of atoms near the interface control their catalytic behavior. Furthermore, the importance of structural dynamics of interfaces is highlighted. We pay particular attention to how microscopy, spectroscopy, and theory can be used in concert to provide insights into the behavior of these systems. We end with a forward-looking discussion on the frontiers in this field and the potential for directing catalytic reactivity by controlling the quantity and nature of metal-support interfaces.