Kinetic study of CTMA+ removal from the pores of the Ti-MCM-41 molecular sieve

• Autor(a) principal: Melo, Marcus Antonio de Freitas
• Data de Publicação: 2014
• Outros Autores: Fontes, Maria do Socorro Braga, Melo, Dulce Maria de Araújo, Barros, Joana Maria de Farias, Braga, Renata Martins, Fontes, Vilsinéia dos Anjos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/45411
• topic: Ti-MCM-41; Molecular sieve; Hydrothermal synthesis; Kinetics

Thermogravimetry analysis was used to study the thermal decomposition of Ti-MCM-41 to determine the best calcination conditions. Ti-MCM-41 molecular sieve was synthesized using a hydrothermal route in which Ti ions were incorporated into the pore channels of MCM-41 starting from a hydrogel method according to the following molar composition: 1.00 CTMABr:4.00 SiO2:X TiO2:1.00 Na2O:200.00 H2O. Physicochemical properties of samples were investigated using XRD, FTIR, and N2 adsorption– desorption to confirm the incorporation of TiO2 nanoparticles inside of MCM-41 mesoporous without destroying its structure. The high temperatures facilitate the rapid removal of the surfactant; however, it caused destruction of the MCM-41 structure by breaking the bonds of the silica tetrahedral structure. The procedures to obtain the apparent activation energies of CTMABr decomposition were based on the kinetic model proposed by Flynn-Wall using thermal analysis of data performed with heating rates 5, 10, and 20 C min-1