The effect of surface phase oxides on the properties of supported metals and catalysis

Abstract

Metal–support interactions have a strong and pivotal influence on catalyst properties. In many cases, these interactions can direct reaction activity, stability, and selectivity. Hence, controlling such interactions has high potential for enhancing catalytic performance. One approach to controlling metal–support interactions is to use a surface phase oxide, wherein a thin layer of a metal oxide is deposited on the surface of an underlying support material to form a hierarchical structure. The addition of a surface phase oxide, as an intermediate between the metal and the underlying support, offers greater possibilities for controlling the metal support interactions by tuning the composition and architecture of both support components. In this review, we discuss current knowledge of surface phase oxides from both experimental and computational points of view. Specifically, we discuss their surface and chemical properties, their effect on supported metal particles, and their catalytic performance. We compare surface phase oxides with other architectures, such as bulk oxides and supported metal oxide particles, and describe cases in which this hierarchical configuration has been applied to significantly enhance catalytic reforming, hydrogenation, and hydrogenolysis reactions. Finally, we highlight aspects that warrant future research and review opportunities for tailoring the performance of next-generation supported metal catalysts.