Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/63807
Type: Artigo de periódico
Title: EFFECT OF CHROMIUM ON MAGNETITE FORMATION
Author: RANGEL, MD
SASSAKI, RM
GALEMBECK, F
Abstract: Chromium-doped magnetite is the traditional catalyst used in the high temperature shift reaction in industrial processes. This work reports a method for preparing this solid, by heating chromium-doped iron(III)hydroxoacetates (IHA), prepared both by coprecipitation and by impregnation. This method provides the production of the catalyst in its active form avoiding the step of activation in industrial processes. It was noted that the presence of chromium affects magnetite formation as well as its characteristics. IHA containing chromium produces magnetite at higher temperature than does the pure IHA. Chromium-doped magnetites have higher surface areas, are less crystalline, have lower Fe(II)/Fe(III) ratios and are catalysts more active than those obtained from plain IHA. These effects depend on the preparation method of the precursor. It was also found that the impregnated sample is made of aggregates of a few crystals whereas the coprecipitate is made of smaller polycrystalline particles. In addition, the coprecipitation method leads to a more even distribution of chromium in solids. These observations are consistent with the best performance shown by the catalyst prepared by coprecipitation.
Subject: MAGNETITE FORMATION
CHROMIUM-DOPED MAGNETITE
HTS CATALYST
IRON(III)HYDROXOACETATE
Country: Holanda
Editor: Baltzer Sci Publ Bv
Rights: fechado
Identifier DOI: 10.1007/BF00814228
Date Issue: 1995
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
WOSA1995RN29200004.pdf2.27 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.