"Síntese e caracterização de catalisadores de ferro e rutênio suportado na zeólita beta".

Abstract

The zeolites are technologically important aluminosilicates and applications in a number of chemical processes. Are widely used as catalysts in acid catalysis reactions in the production of petrochemicals and fine chemicals. Its activity is attributed to the characteristics acids from the Bronested and / or Lewis sites. Beta zeolite is the only zeolite with high Si / Al ratio with a three-way interconnected pore channels. Its characteristics of high acidity, thermal and hydrothermal stability and ease of diffusion of molecules through their relatively large channels, makes this zeolite an very interesting material from the catalytic point of view. It has been used as catalysts in the cracking and isomerization of petroleum fractions. In this work, syntheses of the Beta zeolite support with a molar ratio TEA2O / AI2O3 = 12.5, where the source was the hydroxide of tetraethylammonium. The crystallization time was 4 days at a temperature of 130 ° C. The exchange of the sodium cation of compensation was also carried out by iron and ruthenium, using Iron Nitrate and Hexamine Ruthenium Chloride as solutions. For the ionic exchange of sodium by iron and ruthenium were used as iron nitrate under different concentrations (1.0 M, 0.1 M, 0.05 M, 0.01 M, 0.002 M and 0.005 M) and the hexamine ruthenium chloride at 0.002 M and 0.005M respectively. XRD and SEM analyzes were performed, which confirmed the crystallinity and particle size, with average order of 0.5um. Flame photometry analyzes were also performed, where it was possible to verify that the amount of sodium present in the original sample was reduced when compared to the samples exchanged. From the chemical analyzes by atomic absorption spectroscopy it is possible to determine the chemical composition of the BEA sodium sample and the samples exchanged with 0.1M Iron, where it was found once again that the was efficient for the Beta zeolite with The chemical composition of the sodium sample and the ruthenium exchange identified by X-ray Energy Dispersion (EDX). In the thermal analyzes it was possible to verify the mass variation in temperature, where four distinct regions were identified. THE The first region is associated with beta zeolite dehydration and the other three regions are related to the oxidation of the driver.