CABRAL, R. P. B.; http://lattes.cnpq.br/0276551495615763; CABRAL, Rucilana Patrícia Bezerra.
Résumé:
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.
