Catalytic performance in the complete acetone oxidation of manganese and cobalt oxides supported on alumina and silica

摘要

A series of γ-alumina-and silica-supported oxides as Mn_2O_3, Co_3O_4 and Sm-Mn, Sm-Co bimetallic combinations was prepared by incipient wetness impregnation of the supports with aqueous solutions containing the nitrates of the metals and citric acid. The results obtained with these catalysts in the acetone complete oxidation reaction have shown a predominant effect of the support and the transition metal nature. The silica-supported oxides exhibited a bulk-like behaviour with relatively little difference between the Mn and Co catalysts. In contrast, when supported on alumina the performance of the Mn catalysts was remarkably better than that of the Co-based ones. In this case, whereas the Sm-Mn catalysts maintained a rather good performance relative to that of Mn/Al_2O_3, the temperatures required for acetone combustion over the Sm-Co catalysts were significantly lower than the ones over Co/Al_2O_3.