Palladium nanoparticles
Palladium nanoparticles Palladium nanoparticles play an important role in catalysis. For hydrogenation of hydrocarbons, such as alkynes and alkenes, palladium is recognized as the preferred catalyst. In reaction conditions, palladium nanoparticles may undergo phase changes to hydride and carbide phases, whose natures affect the catalytic properties. Therefore, determining the hydride and carbide formation during a catalytic process becomes an important problem, also relevant to industry. Being a subject of numerous theoretical and experimental  studies, palladium hydride is one of the most-studied metal hydrides. In contrast to the hydride, the structure and properties of the carbide phase are still under discussion.
The aim of the current work is to present a systematic approach for in situ and operando investigation of the formation of hydride and carbide phases in an industrial palladium-based catalyst. We show that simultaneous utilization of XRPD, EXAFS and XANES allows obtaining complimentary information on the nanocatalyst structure. A special role in discriminating between hydride and carbide phases is given to XANES. The changes observed in XANES spectra of the palladium catalyst under reaction conditions are reproduced by theoretical simulations.

Members:  Aram Bugaev / Alexander Guda / Kirill Lomachenko / Carlo Lamberti
Collaborations:  ETH Zurich / Paul Sherrer Institute / University of Turin
Grants:  Mega-Grant / President Grant (Pd, CeO2)