New reactor dedicated to in operando studies of model catalysts by means of surface x-ray diffraction and grazing incidence small angle x-ray scattering

Journal Article · Wed Aug 15 04:00:00 EDT 2007 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.2766821· OSTI ID:21024140

Saint-Lager, M -C; Bailly, A; Dolle, P; Baudoing-Savois, R; Taunier, P; Garaudee, S; Cuccaro, S; Douillet, S; Geaymond, O; Perroux, G; Tissot, O; Micha, J -S; Ulrich, O; Rieutord, F ^[1]

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1. Institut Neel, CNRS and Universite Joseph Fourier, BP 166, F-38042 Grenoble Cedex 9 (France)

A new experimental setup has been developed to enable in situ studies of catalyst surfaces during chemical reactions by means of surface x-ray diffraction (SXRD) and grazing incidence small angle x-ray scattering. The x-ray reactor chamber was designed for both ultrahigh-vacuum (UHV) and reactive gas environments. A laser beam heating of the sample was implemented; the sample temperature reaches 1100 K in UHV and 600 K in the presence of reactive gases. The reactor equipment allows dynamical observations of the surface with various, perfectly mixed gases at controlled partial pressures. It can run in two modes: as a bath reactor in the pressure range of 1-1000 mbars and as a continuous flow cell for pressure lower than 10{sup -3} mbar. The reactor is connected to an UHV preparation chamber also equipped with low energy electron diffraction and Auger spectroscopy. This setup is thus perfectly well suited to extend in situ studies to more complex surfaces, such as epitaxial films or supported nanoparticles. It offers the possibility to follow the chemically induced changes of the morphology, the structure, the composition, and growth processes of the model catalyst surface during exposure to reactive gases. As an example the Pd{sub 8}Ni{sub 92}(110) surface structure was followed by SXRD under a few millibars of hydrogen and during butadiene hydrogenation while the reaction was monitored by quadrupole mass spectrometry. This experiment evidenced the great sensitivity of the diffracted intensity to the subtle interaction between the surface atoms and the gas molecules.

• OSTI ID: 21024140
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 8 Vol. 78; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AUGER ELECTRON SPECTROSCOPY
BUTADIENE
CATALYSTS
ELECTRON DIFFRACTION
EPITAXY
FILMS
GASES
HYDROGEN
HYDROGENATION
MASS SPECTROSCOPY
MORPHOLOGY
NANOSTRUCTURES
PARTIAL PRESSURE
SMALL ANGLE SCATTERING
SURFACES
X RADIATION
X-RAY DIFFRACTION