Iron Manganese mixed oxide catalysts for ethanol combustion. Influence of the Fe|Mn atomic ratio and the calcination temperature

Abstract

A Fe-Mn mixed oxide catalyst for eth- anol combustion was optimized using different Fe:Mn atomic ratios and varying the calcination temperature (500ºC, 650ºC and 800ºC). The results indicated that the increase of the calcination temper- ature caused a decrease of the catalytic activity due to a strong decrease of the specific surface area. Then, among the catalysts calcined at 500ºC, the most active one was the catalyst with lower amount of iron. The results of X-ray diffraction (XRD) and temperature programmed reduction (TPR) indicated that a small amount of iron in the Fe-Mn mixed cata- lyst favored the formation of dispersed surface amorphous MnOx species. These species are easily reducible and very active in total oxidation reactions.