AB STRACT: (Lanthanum, Cerium)(Iron, Manganese, Cobalt, Palladium)(Oxygen) 3 -Perovskite catalyst was prepared by the citrate route and deposited on ceramic monoliths via dip coating procedure. The catalyst was applied on a car with XU7 motors and the amount of emission was monitored with vehicle emission test systems in Sapco company. The results were compared with the imported catalyst with noble metals such as palladium, platinum and rhodium by Iran Khodro company based on the Euro III standards. The catalysts were characterized by specific surface area measurements, scanning electron microscopy, X-ray diffraction, line scan and map. In the results, obtained in the home made sample, the amount of carbon monoxide, nitrogen oxides and hydrocarbons were lower than imported catalyst with Iran Khodro company with nobel metals. The illustration shows nano particles size on coat. The microstructure evaluation showed that the improved properties can be related to the existence of nano particles on coating.
Square wave cathodic current modulation was used to electrodeposit nanostructured platinum on niobium. The crystallite size, surface morphology and active surface area of deposits were strongly dependent on the process parameters such as pulse duty cycle, peak current density and pulse frequency. Microstructure, surface morphology and grain size of the deposits were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Cyclic voltammetry was also used to determine the deposit's effective surface area. The best quality platinum coated electrode was obtained from the pulse plating condition of 15 Hz frequency, 9 mA cm 22 peak current density and 30% duty cycle. Moreover, AFM observations demonstrated that the best quality Pt/Nb electrode has the highest active surface area f r of 281 cm 2 with the finest grain size of 52 nm. This means that the structure of the coating can be controlled by the electrodeposition parameters resulting in an increased electrochemical surface area.
BaTi1−x
NbxO3 compounds (with x = 0.0, 0.01, 0.03, 0.06, and 0.09) were synthesized by rotary-hydrothermal (RH) method. The process was conducted at 180 °C for 5 hours in a Teflon vessel that was rotated at a speed of 160 rpm during the hydrothermal reaction. The effects of donor concentration on the structure and properties of BaTi1−x
NbxO3 compounds were investigated. The experiments for the BaTiO3±Nb2O3 system produced by a solid state reaction at high temperature at different concentrations of niobium, with the use of RH processing have not been reported in previous works. For the phase evolution studies, X-ray diffraction patterns (XRD) were analyzed and Raman spectroscopy measurements were performed. The transmission electron microscope (TEM) and the field emission scanning electron microscope (FE-SEM) images were taken for the detailed analysis of the grain size, surface and morphology of the compound.
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