Original scientific paper
RHEED and TPD studies of the effect of particle size on CO desorption from Al2O2 supported Pd and Rh model catalysts
Vladimír Matolín
; Department of Electronics and Vacuum Physics, Charles University, V Holesovickach 2, 180 00 Prague 8, Czech Republic
Abstract
Transition metals in form of small supported particles are frequently used in heterogeneous catalytic reactions. One point of actual interest concerns the reactivity of low co-ordination sites characteristic for particle surface. The non continuous epitaxial layers of Pd and Rh were grown on insulator substrates (Al2O3) by molecular beam epitaxy. The reflection high energy electron diffraction (RHEED) offered a readily applicable method for in-situ observation of epitaxial layer growth. As a model reaction CO adsorption was studied by means of the temperature programmed desorption (TPD) using a differentially pumped mass spectrometer with a molecular beam doser. It was shown that the activation energy of CO desorption decreases with decreasing particle size.
Keywords
Hrčak ID:
299467
URI
Publication date:
2.5.1995.
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