The influence of La2O3-doping on structural, surface and catalytic properties of nano-sized cobalt–manganese mixed oxides

International Journal of Industrial Chemistry

دوره 7، شماره 3، آذر 2016، صفحه 287-296

نوع مقاله: research article

شناسه دیجیتال (DOI): https://doi.org/10.1007/s40090-015-0068-2

نویسندگان

Abdelrahman A. Badawy^{* 1}؛ Shaimaa M. Ibrahim^{2، 3}

¹Physical Chemistry Department, National Research Centre, Dokki, Cairo, Egypt

²Chemistry Department, Faculty of Education, Ain Shams University, Cairo, Egypt

³Present address: Department of Chemistry, Faculty of Science, Qassim University, Buraidah, Saudi Arabia

چکیده

Structural, textural and catalytic activity of CoO–Mn₂O₃ system as being influenced by La₂O₃-doping (0.75–3 mol%) and calcination temperatures (300–500 °C) were investigated. The techniques employed were XRD, N₂-adsorption–desoprtion at −196 °C, EDX and catalysis of H₂O₂-decomposition in aqueous solution at 30–50 °C. The results revealed that the investigated system consisted of nano-sized Co₂MnO₄ as a major phase together with un-reacted portion of Co₃O₄ and γ-Mn₃O₄. Doping with the smallest amount of La₂O₃ greatly increased the surface molar ratio of Mn/Co (88 %) for the solid calcined at 500 °C with subsequent increase of the catalytic activity more than 12-fold for solids calcined at 500 °C. The increase of La₂O₃-dopant above 0.75 mol% decreased progressively the surface molar ratio of Mn/Co with subsequent decrease in the catalytic activity which still measured higher values than that measured for the un-doped catalyst.

کلیدواژه‌ها

Cobalt manganite؛ La2O3-dopant؛ Coprecipitation؛ Catalytic decomposition of H2O2