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Y and ZSM-5 Hierarchical Zeolites Prepared Using a Surfactant-Mediated Strategy: Effect of the Treatment Conditions.
Ruggiu, Andrea; Carvalho, Ana Paula; Rombi, Elisabetta; Martins, Angela; Rocha, João; Parpot, Pier; Neves, Isabel C; Cutrufello, Maria Giorgia.
Afiliación
  • Ruggiu A; Department of Chemical and Geological Sciences, University of Cagliari, Complesso Universitario di Monserrato, S.S. 554, 09042 Monserrato, CA, Italy.
  • Carvalho AP; National Interuniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
  • Rombi E; Centro de Química Estrutural, Institute of Molecular Sciences, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
  • Martins A; Departamento de Química e Bioquímica, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
  • Rocha J; Department of Chemical and Geological Sciences, University of Cagliari, Complesso Universitario di Monserrato, S.S. 554, 09042 Monserrato, CA, Italy.
  • Parpot P; National Interuniversity Consortium of Materials Science and Technology (INSTM), Via Giusti 9, 50121 Florence, Italy.
  • Neves IC; Centro de Química Estrutural, Institute of Molecular Sciences, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
  • Cutrufello MG; Departamento de Engenharia Química, Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, Rua Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal.
Materials (Basel) ; 17(17)2024 Sep 06.
Article en En | MEDLINE | ID: mdl-39274788
ABSTRACT
Diffusional limitations associated with zeolite microporous systems can be overcome by developing hierarchical zeolites, i.e., materials with a micro- and mesoporous framework. In this work, Y and ZSM-5 zeolites were modified using a surfactant-mediated hydrothermal alkaline method, with NaOH and cetyltrimethylammonium bromide (CTAB). For Y zeolite, after a mild acidic pretreatment, the effect of the NaOH+CTAB treatment time was investigated. For ZSM-5 zeolite, different concentrations of the base and acid solutions were tested in the two-step pretreatment preceding the hydrothermal treatment. The properties of the materials were studied with different physical-chemical techniques. Hierarchical Y zeolites were characterized by 3.3-5 nm pores formed during the alkaline treatment through the structure reconstruction around the surfactant aggregates. The effectiveness of the NaOH+CTAB treatment was highly dependent on the duration. For intermediate treatment times (6-12 h), both smaller and larger mesopores were also obtained. Hierarchical ZSM-5 zeolites showed a disordered mesoporosity, mainly resulting from the pretreatment rather than from the subsequent hydrothermal treatment. High mesoporosity was obtained when the concentration of the pretreating base solution was sufficiently high and that of the acid one was not excessive. Hierarchical materials can be obtained for both zeolite structures, but the pretreatment and treatment conditions must be tailored to the starting zeolite and the desired type of mesoporosity.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Materials (Basel) Año: 2024 Tipo del documento: Article País de afiliación: Italia Pais de publicación: Suiza
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Materials (Basel) Año: 2024 Tipo del documento: Article País de afiliación: Italia Pais de publicación: Suiza