Caracterização das zeólitas ZSM-12 sintetizadas pelo método hidrotérmico utilizando cloreto de metiltrietilamônio e n-butilamina como agentes direcionadores de estrutura

Abstract

Zeolites are of great industrial interest due to the unique properties of these materials, such as well-defined porosity and adjustable composition, contributing to their use in several technological areas such as the petrochemical, oil and fine chemical sectors. Among the various zeolites of industrial interest, ZSM-12 can be mentioned, which, due to its excellent shape selectivity, has been highlighted as a catalyst in many industrial processes, such as: catalytic cracking, benzene alkylation, xylene isomerization, n-paraffin hydroisomerization reactions, among other applications. Zeolites can be synthesized by different methods, the hydrothermal method being the most reported in the literature because it has a higher rate of reproducibility and application on an industrial scale. In this context, the objective of this work was to carry out the synthesis of the zeolite ZSM-12 by the hydrothermal method at 160 ºC using methyltriethylammonium chloride (MTEACl) as a structure directing agent with different concentrations (0.15, 0.20 and 0.25), combined or not with n-butylamine, and SiO2/Al2O3 ratio (SAR) equal to 100 and 150, verifying the influence on their physicochemical properties, in order to identify the best synthesis route in the proposed system. The synthesized zeolites were characterized by X-ray diffraction, whose graphs were used to perform the refinement of structures by the Rietveld method and to obtain the unit cell lattice parameters. Thermogravimetric and nitrogen adsorption/desorption analyzes were also carried out. The synthesis of zeolite ZSM-12 was successfully performed in the present work, proving the effectiveness of using MTEACl and n-butylamine. From the results obtained in the characterizations, the presence of typical properties of zeolites can be observed.