In situ formation of hydrides and carbides in palladium catalyst: When XANES is better than EXAFS and XRD
Articolo
Data di Pubblicazione:
2017
Abstract:
In a number of hydrogenation reactions, palladium nanoparticles may undergo a transition to the hydride or the carbide phase, which affects the catalytic properties. In the current work, we determine the structural evolution of an industrial Pd/C catalyst in the presence of hydrogen and acetylene by means of in situ X-ray absorption spectroscopy and X-ray powder diffraction. We observe reversible hydride phase formation and irreversible formation of the carbide phase. The near-edge structure of the absorption spectra (XANES) plays the key role in distinguishing between hydride and carbide phases. We show that the presence of hydrogen and carbon atoms have a direct effect on the near-edge region which is reproduced by theoretical simulations performed in the Monte-Carlo approach.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
EXAFS; Monte Carlo simulations; Palladium carbide; Palladium hydride; XANES simulations; XRPD; Catalysis; Chemistry (all)
Elenco autori:
Bugaev, Aram L.; Guda, Alexander A.; Lazzarini, Andrea; Lomachenko, Kirill A.; Groppo, Elena; Pellegrini, Riccardo; Piovano, Andrea; Emerich, Hermann; Soldatov, Alexander V.; Bugaev, Lusegen A.; Dmitriev, Vladimir P.; van Bokhoven, Jeroen A.; Lamberti, Carlo
Link alla scheda completa:
Link al Full Text:
Pubblicato in: