Hydrogen peroxide decomposition over La_0.9Sr _0.1Ni_{1 - x}Cr_xO₃ perovskites

Mixed oxides of the type La_0.9Sr_0.1Ni _1-xCr_xO₃ (0≤x≤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 La _0.9Sr_0.1Ni_1-xCr_xO₃ phases have the rhombohedral (x≤∼0.3) and the orthorhombic structure (x≥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.