Magnetite Formation on Silica and Alumina

Abstract

Iron(III)hydroxoacetate (IHA) was precipitated on (i) silica and (ii) alumina and heated, under conditions at which IHA yields magnetite, according to a new, recently published route for magnetite preparation. In the presence of silica, magnetite formation is prevented. Magnetite obtained by beating IHA deposited on alumina is less crystalline and has a lower Fe(II)/Fe(III) ratio than the unsupported material. Magnetite coatings on alumina are uneven, a feature which is related to the heterogeneity in the morphology of alumina particle surfaces: rougher surfaces are more Intensely coated than smoother ones.