Preparartion and characterization of terbium over paligorsquite clay as acid catalyst

Palygorskite clays containing 5% and 10% terbium (W/W) were prepared by ion exchange from acid-leached naturalclay. Samples were calcined at 523, 573, 623 and 673 K to verify the e ect of the temperature over the physical±chemicalproperties. Characterization was using X-ray di raction, infrared spec...

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Detalles Bibliográficos
Autores: Melo, Marcus Antônio de Freitas, Ruiz, Juan Alberto Chavez, Melo, Dulce Maria de Araújo, Vitor Sobrinho, Eledir, Schmall, M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:Brasil
Institución:Universidade Federal do Rio Grande do Norte (UFRN)
Repositorio:Repositório Institucional da UFRN
Idioma:inglés
OAI Identifier:oai:repositorio.ufrn.br:123456789/45119
Acceso en línea:https://repositorio.ufrn.br/handle/123456789/45119
Access Level:acceso abierto
Palabra clave:Palygorskite
Mineral clays
Dehydration
Isopropyl alcohol
Descripción
Sumario:Palygorskite clays containing 5% and 10% terbium (W/W) were prepared by ion exchange from acid-leached naturalclay. Samples were calcined at 523, 573, 623 and 673 K to verify the e ect of the temperature over the physical±chemicalproperties. Characterization was using X-ray di raction, infrared spectroscopy (n-butylamine adsorption), UV±visibledi use reØectance spectroscopy and N2adsorption. Isopropyl alcohol (IPA) transformation was also performed inorder to improve the acid behavior. TB3áintroduction does not change the palygorskite structure, albeit leading to anincrease in the surface area and generation of Lewis acid sites. Results from the DRS spectra along with a decrease inthe catalytic activity suggested the formation of terbium oxide for relatively high TB3ácontents