ISSN:
1573-4854
Keywords:
ferrihydrite
;
hematite
;
BET
;
porosity
;
catalyst
;
transformation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Ferrihydrite is a poorly-ordered iron oxyhydroxide which possesses a high specific surface area (〉200 m2/g). This makes it an important constituent for surface related processes in nature and catalysis. This study focuses on the precautions that have to be taken in the sample preparation prior to BET measurements in order to avoid essential structural transformations. The experiments showed that temperatures between 90 and 120°C are necessary to remove surface contaminations and simultaneously prevent structural transformation of the ferrihydrite during the outgassing procedure. Furthermore, care has to be taken to keep the humidity low in the immediate proximity of the sample, due to the strong impact of this parameter on the structural stability of ferrihydrite.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009610800182
