Study of effect of preparation method and composition on the catalytic properties of complex oxides (Gd,Sr)n + 1FenO3n + 1 for dry reforming of methane

Resumo

The catalytic activity of nanostructured perovskite-type ferrites of gadolinium and strontium, has been studied. The intercorrelation between the catalytic activity and the method used to obtain ferrites has been shown: the products formation rates are higher in the samples obtained by a ceramic technology, while the sol-gel method makes it possible to obtain ferrites with a greater hydrogen selectivity, which is accounted for by their nanocrystalline state and porous structure. It is shown that the specific catalytic activity of the catalysts, which are prepared by the same method and are of approximately the same chemical composition, is constant. It is shown that a nonisovalent replacement of gadolinium by strontium causes symmetry lowering in the perovskite structure and the appearance of a heterovalent state of iron atoms, which affects ferrite catalytic activity.