Morphology, oxygen vacancies, and other factors affecting the performance of supported bimetallic ceria catalysts.

Abstract

Here in we report the development of a Pt-V/CeO2 catalyst performing under mild conditions in amide hydrogenation. Ceria with different morphologies was employed as support in this study. We further developed a glycol-thermal technique that yields thermally stable quantum dot ceria, which can be applied as a support. A systematic investigation revealed the importance of proximity between the small crystalline hydrogenating sites (Pt) and oxophilic sites (V). The study showed that oxygen vacancies on the ceria surface oxidize both Pt and V, poisoning the hydrogenation reaction. In contrast, the absence of oxygen vacancies promoted the hydrogenating ability of Pt sites and also improved their ability to participate in the H2 spillover mechanism and in situ formation of oxophilic V3+. This study demonstrates how the engineering of the oxygen vacancies on the surface of the redox support can manipulate the nature of active sites toward specific reactions.