Transição de fases de zeólita do tipo Faujasita para Sodalita via tratamento térmico

Abstract

The zeolites can have several functions as catalysts (biofuel production) and molecular sieves (treatment of contaminated areas). This study aims to characterize the zeolites obtained in the transition of a Faujasite like zeolite into a Sodalite, when submitted to different thermal treatment times. The synthesized zeolites were characterized by X-ray diffraction where the crystalline phases were identified: Faujasite, Sodalite, SiO₂ and amorphous material. The 4 hours heat treatment produces zeolite crystal structure similar to Faujasite, having basic sites, surface area of 552.7 m² g^-1 , and pore volume of 0.3391 cm³ g^-1. With increasing time of heat treatment was observed the transition to the Sodalite phase witch containing 0.277 mmol g^-1 of basic active sites with surface area of 11.38 m² g^-1 and pore volume of 0.0651 cm³ g^-1. By the Rietveld method was identified and quantified the presence of Sodalite and Hidrossodalite in samples with 24 and 30 hours of reaction times.