Preparation and Physical Chemistry Characterization of New Nanostructured Oxides Catalysts by Spray Pyrolysis Method for the Biodiesel Production

Abstract

In this work were synthesized new catalysts of stoichiometries Sr0.8K0.2TiCu0.10O3, Sr0.7K0.3TiCu0.15O3 and Sr0.5K0.5TiCu0.25O3 by spray pyrolysis method. The synthesis conditions were optimized to obtain single phase powder of titanates of double perovskite structure, with an ultrasound vibration frequency of 1.3 MHz at 700 °C under air flow. The average crystallite size of the powders, determined by the Scherrer equation and using the Jade Plus 8 software, was at around 9 nm. The powder morphology was analyzed by scanning electron microscopy (SEM). The Sr0.5K0.5TiCu0.25O3 system showed particles with smooth surfaces, spherical and with smaller agglomerates than Sr0.8K0.2TiCu0.10O3, Sr0.7K0.3TiCu0.15O3 systems. This phenomenon suggests that the stoichiometry changes the aspect of the particle surface, which may influence in the catalytic activity. Thus, particles without roughening and smaller size can act as promising catalysts.

A review of advances in multifunctional XTiO3 perovskite-type oxides as piezo-photocatalysts for environmental remediation and energy production

“…Operating frequencies between 1.30 and 1.67 MHz have been reported, with formation of droplets of ca. 6 m [83][84][85]. Chou [83] and Li [84] performed the synthesis of SrTiO3 samples with different morphologies by dissolving the precursor into nitric acid solution and by addition of hydroxyl source such as hydrogen peroxide, glycerol or 1,2-propanediol.…”

“…Lanfredi et al [85] prepared several strontium titanate based materials where both Ti and Sr were partially substituted by Cu and K, respectively, to obtain a performing catalyst for biodiesel production. The optimization was carried out by tuning the temperature of the CEF (700-900°C), the flow rate of the carries gas (air, 3-6 L/min) and the concentration of the precursor solution (0.025-0.5 M).…”