Catalytic properties of nanocomposites based on cobalt ferrites dispersed in sol脙脙脙脙脙脙gel silica

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• 作者：Silva ; Juliana B. ; Diniz ; Cristina F. ; Lago ; Rochel M. ; Mohallem ; Nelcy D.S.
• 关键词：C130 ; C230 ; S160 ; S300
• 刊名：Journal of Non-Crystalline Solids
• 出版年：2004
• 期刊代码：50_00223093
• 类别：ms
• 出版时间：November 15, 2004
• 卷：348
• 期：Complete
• 页码：201-204
• 文件大小：344 K

摘要

In this work, composites based on cobalt ferrite (CoFe₂O₄) dispersed in a porous silica matrix have been prepared via sol芒芒芒gel method using tetraethylorthosilicate (TEOS) as a silica precursor, and iron and cobalt nitrates as precursors. In this process, Co and Fe ions dispersed in a sol芒芒芒gel matrix reacted upon thermal treatment to form Co芒芒芒Fe crystallites with nanometric dimensions. The structural, morphological, and textural changes of the composites treated at various temperatures were studied by X-ray diffraction, electronic microprobe, and gas adsorption. The treated composites had surface areas in the range 263芒芒芒359m²g^芒芒芒1 with mesopore contribution. These materials were active as catalysts in the total oxidation of chlorobenzene in air. The most active catalyst was the composite treated at 500芒芒C, which was stable at a temperature as high as 600芒芒C for 72h.