ISSN:
1572-8943
Keywords:
graphic method
;
kinetic parameters
;
PdO/Al2O3
;
TPD
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract A graphic method is proposed to determine all of the kinetic parameters in Wigner-Polanyi equation of desorption. A desorption rate curve from a single temperature-programmed desorption experiment is required by this method to determine the order of reaction (n), the activation energy (E d) and the pre-exponential factor (v) of the equation. The proposed method has been applied to the oxygen desorption from PdO/Al2O3 samples prepared by impregnating γ-Al2O3 with H2PdCl4 solution used as examples. From the graphic method, the values ofn=2, andv=1.37±0.80×109 s−1 were successfully determined for the desorption. The value ofE d depended on the dispersion of palladium (D) on PdO/Al2O3 samples, and was expressed by the equation:E d=175+174D kJ·mol−1. This graphic method is a direct and time-saving technique, on comparing with other methods suggested in the literature, for analysis of data from temperature-programmed desorption of simple desorption processes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01979970
Permalink
