La1−xCaxAl1−yNiyO3 perovskites used as precursors of nickel based catalysts for ethanol steam reforming

On the search of new design procedures for high performance catalysts we have obtained a very precisely defined surface architecture starting from a particular host structure. In this case, high purity La1−xCaxAl1−yNiyO3 (x = 0, 0.1; y = 0.1, 0.2, 0.3) perovskites were chosen, prepared by the citrate method and evaluated in the ethanol steam reforming reaction. The samples were characterized by X-ray diffraction (XRD), specific surface area measurements, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge structure (XANES) and extended X-ray adsorption fine structure (EXAFS), temperature-programmed reduction (TPR) and Hydrogen Chemisorption. All the samples presented an excellent catalytic activity and stability. Exceptionally high H2 yield values and low CO and CH4 selectivities were observed. Perovskite without the addition of Ca and with a value of y = 0.2 presented the highest stability during 12 h on stream.