ISSN:
1572-879X
Keywords:
nitric oxide
;
rhodium
;
dissociation kinetics
;
static secondary ion mass spectrometry
;
temperature-programmed desorption
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The desorption and dissociation of nitric oxide on a polycrystalline Rh foil were studied by means of combined temperature-programmed desorption (TPD) and static secondary ion mass spectrometry (SSIMS). The latter method was employed either under isothermal conditions or in a temperature-programmed mode (TPSSIMS). After carefully calibrating the secondary ion intensities by means of TPD, the NO dissociation kinetics were quantitatively evaluated for low NO coverages. Fitting the SSIMS data with a Polanyi-Wigner ansatz and assuming first-order kinetics, we found an activation energy,E=8±2 kJ/mol, and a preexponential,v=100.2±0.4s−1. The data were confirmed by independent isothermal SSIMS measurements at several temperatures between 80 and 330 K. The fairly unusual rate parameters are discussed in relation to similar results obtained recently from measurements on Rh single crystal surfaces.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00807014
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