ISSN:
1573-4846
Keywords:
hollandite
;
tunnel structure
;
NO adsorption
;
DRIFTS
;
TPD
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Fine powder of K x Ga x Sn8−x O16 hollandite was prepared by the sol-gel process using metal alkoxides, and the adsorption behavior of nitrogen monoxide (NO) on it was examined by temperature programmed desorption (TPD) method and in situ diffuse reflectance fourier transform infrared spectroscopy. Any species other than nitrogen monoxide were not detected in the TPD measurement, and the profile showed three stages between 420 and 880 K which were regarded as the desorption of chemically adsorbed NO x species. This desorption behavior seems well consistent with the spectral changes in the FT-IR measurement. The absorption band at 1270 cm−1 was decayed in the first stage from 420 to 640 K, and the bands at 1235 and 1570 cm−1 in the second stage from 640 and 770 K. In the third stage above 770 K, the strong band at 1340 cm−1 disappeared. These NO x species on the hollandite were estimated to have a form of NO3 − in the first and second stages and a form of NO2 − in the third stage, considering the data on adsorption of nitrogen oxides on La2O3 and CaO.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008722824410
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