Influência do uso de surfactante e direcionador de estrutura no grau de desorganização na estrutura zeolítica MWW

Abstract

In this work a study was carried out aiming to obtain the disorganized MCM-22 (P) by direct synthesis using a dual-template system with hexamethyleneimine and cetyltrimetylammonium hydroxide as structure director and delaminating agente, respectively. This study aims to optimize the modification process that promotes disorganization of the lamellae zeolitic precursor and makes the active sites more accessible. Through the total analysis it is possible to estimate that the decrease of the HMI allows a greater incorporation of CTMAOH/Br in the material. In addition, the syntheses were performed with hexamethyleneimine mass reduced by up to 40%, also seed were used in all synthesis. It was observed by X-ray diffractograms that the presence of the surfactant CTMAOH/Br depending on the quantity, can promote the disorganization of the lamellae and act as a structure director compensating for the lower amount of HMI. Were performed synthesis with Si/Al = 15 and Si/Al = 50 ratios, and it was found that the synthesis with Si/Al = 50 ratio have more difficult in the crystallization process, and amorphous solids or early crystallization stages are obtained.