In situ determination of the active phase in palladium nanocatalyst by X-ray absorption spectroscopy and X-ray diffraction

5 Jul 2016, 15:00
1h
2nd and 3rd floors (Budker INP)

2nd and 3rd floors

Budker INP

Board: 017

Speaker

Mr Aram Bugaev (Southern Federal University)

Description

Hydrogenation of alkynes and alkenes over palladium catalyst is associated with formation of palladium hydrides and carbides phases, which affects the selectivity and catalytic performance of the catalyst. The aim of this study is to investigate the effect of the structural changes on the catalytic properties of the material. We investigated the structural evolution of the industrial palladium-based nanocatalyst in operando conditions during the catalytic hydrogenation of ethylene. The structure of the catalyst was followed by X-ray absorption spectroscopy and X-ray powder diffraction, while the conversion level of ethylene to ethane was controlled by mass spectrometer. We observed that phase transitions occurring in palladium nanoparticles lead to dramatic changes of the catalytic activity. In addition to standard Fourier-analysis of X-ray absorption data and Rietveld refinement of diffraction patterns, analysis of X-ray absorption near-edge structure (XANES) allowed to discriminate between PdH and PdC species having similar fcc structure. The PdC phase and pure Pd phase demonstrated extremely high catalytic activity in ethylene to ethane hydrogenation, while β-PdH showed unexpectedly low activity.

Primary author

Mr Aram Bugaev (Southern Federal University)

Co-authors

Dr Alexander Guda (Southern Federal University) Prof. Alexander Soldatov (Southern Federal University) Mr Andrea Lazzarini (University of Turin) Prof. Carlo Lamberti (University of Turin) Dr Elena Groppo (University of Turin) Dr Kirill Lomachenko (Southern Federal University) Dr Riccardo Pellegrini (Chimet) Prof. Vladimir Dmitriev (ESRF)

Presentation Materials

There are no materials yet.