The transition to a CO2-neutral economy requires the development of advanced catalysts for new chemical processes that are based on renewable energy sources instead of fossil fuels. Most of such catalysts are complex nanostructured composites that often have both metallic and oxidized parts. The charge transfer between metal and oxide components strongly affects the catalyst properties and can be engineered to boost the catalytic activity by orders of magnitude. However, such charge transfer is notoriously challenging to characterize experimentally, which puts electronic structure simulations at the forefront of research on complex nanostructured catalysts. This contribution will discuss recent density functional (DFT) simulations and experimental studies of the charge transfer through the metal-oxide interface in a wide range of catalysts. Although the charge accumulated on metal particles supported on oxides is distributed among all surface metal atoms, we show that it affects the properties of various surface sites to a different extent on the example of Pt/CeO2 fuel cell catalysts. In turn, the charge transferred to oxide catalysts may lead to the formation of O vacancies in the catalyst, which, for instance, accelerates methanol production on InOx catalysts supported on Co surfaces. Alternatively, metal-oxide charge transfer may lead to an unusual charge of oxide cations. For example, Mo3+ centers stabilized by interaction with Ni support was found to be responsible for outstanding electrochemical hydrogen evolution activity of NiMo catalysts. Finally, we will also show how the charge transfer between active sites in Ni and Co oxyhydroxide and high-valence metals accelerates the electrochemical oxygen evolution reaction. The discussed studies shed light on the importance of metal-oxide charge transfer on the activity of nanostructured catalysts. They also suggest strategies for how the charge transfer can be controlled by rationally choosing the catalytic support to achieve the superior catalytic activity.

Improving the catalytic activity by nanoscale metal-oxide charge transfer

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.