Hydrogen peroxide decomposition over La0.9Sr0.1Ni1-xCrxO3 perovskites

Mixed oxides of the type La0.9Sr0.1Ni1-xCrxO3 (0 less than or equal to x less than or equal to 1) with perovskite structure were prepared by citrate method. The formation of the perovskite structure has been shown by X-ray diffraction (XRD) for all samples. The La0.9Sr0.1Ni1-xCrxO3 phases have the rhombohedral (x less than or equal to similar to0.3) and the orthorhombic structure (x greater than or equal to 0.4). Particle sizes are in the 14.0-45.5 nm range. Scanning electron microscopy (SEM) and energy dispersive analysis by X-ray (EDX) techniques were used to determine homogeneity of the catalyst. The catalytic properties of these samples also examined using hydrogen peroxide decomposition as a test reaction. it was observed that the catalytic activity of these materials decreased with increasing chromium content in the catalyst. In this situation, it also seems that activation energy, due to the change of structure type and or decrease of high oxidation states of nickel, increases. (C) 2003 Elsevier B.V. All rights reserved.