Influence of anions on the structural and catalytic properties of CTA-MCM-41

Registro completo de metadados
MetadadosDescriçãoIdioma
Autor(es): dc.contributorUniversidade Federal de São Carlos (UFSCar)-
Autor(es): dc.contributorUniversidade Estadual Paulista (UNESP)-
Autor(es): dc.contributorUniversidade Estadual de Campinas (UNICAMP)-
Autor(es): dc.creatorde Assis, Flávio M.-
Autor(es): dc.creatorRibeiro, Maria E.-
Autor(es): dc.creatorZapelini, Iago W.-
Autor(es): dc.creatorLanders, Richard-
Autor(es): dc.creatorCardoso, Dilson-
Data de aceite: dc.date.accessioned2025-08-21T18:51:47Z-
Data de disponibilização: dc.date.available2025-08-21T18:51:47Z-
Data de envio: dc.date.issued2025-04-29-
Data de envio: dc.date.issued2024-11-19-
Fonte completa do material: dc.identifierhttp://dx.doi.org/10.1016/j.colsurfa.2024.134850-
Fonte completa do material: dc.identifierhttps://hdl.handle.net/11449/306623-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/11449/306623-
Descrição: dc.descriptionCTA-MCM-41 — Mobil Composition of Matter 41 with cetyltrimethylammonium cations (CTA+) — is a hybrid silica known for its high basic catalytic activity due to anionic silanolate sites ([tbnd]Si−O-) that are bound to CTA+. The synthesis of this material depends on the properties of CTA+ micelles in aqueous dispersion which, in turn, depend on the surrounding anions. Thus, this study investigated different types and amounts of anions in the synthesis of CTA-MCM-41. Chloride (Cl-), bromide (Br-), iodide (I-), nitrate (NO3-) and hydroxide (OH-) anions in sodium form were added to the synthesis mixture, and the obtained silicas were tested in the transesterification reaction. It is hereby presented a comprehensive study on how micelles-anion interfaces play a key role in the synthesis of this important hybrid silica catalyst, and it was possible to synthesize a more active basic catalyst than the conventional CTA-MCM-41, just by exploring such surface chemistry effects. Three significant features are highlighted: (1) improved catalytic activity of CTA-MCM-41 applied in transesterification; (2) Synthesis of CTA-MCM-41 with higher retention of cations per silica and higher amount of silanolate basic sites; (3) deepening knowledge of the synthesis mechanism of materials from the MCM-41 family. The effects are more pronounced in the order I- > NO3- > Cl-, in accordance with the Hofmeister ion series. Hydroxide anions, however, led to the greatest increase in the number of sites and basic catalytic activity (up to 52.4 %). These results reinforce the validity of the {S+, X-, I-} (S: surfactant; X: anion; I: silica) silica formation mechanism and reveal a synthesis with hydroxide anions that produces a catalyst more active than conventional CTA-MCM-41.-
Descrição: dc.descriptionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)-
Descrição: dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)-
Descrição: dc.descriptionLaboratório de Catálise (LabCat) Universidade Federal de São Carlos, SP-
Descrição: dc.descriptionFaculdade de Engenharia e Ciências Universidade Estadual Paulista, SP-
Descrição: dc.descriptionInstituto de Física Gleb Wataghin Universidade Estadual de Campinas, SP-
Descrição: dc.descriptionFaculdade de Engenharia e Ciências Universidade Estadual Paulista, SP-
Descrição: dc.descriptionCAPES: 001-
Descrição: dc.descriptionCNPq: 132770/2019–9-
Descrição: dc.descriptionCAPES: 88887.509044/2020–00-
Idioma: dc.languageen-
Relação: dc.relationColloids and Surfaces A: Physicochemical and Engineering Aspects-
???dc.source???: dc.sourceScopus-
Palavras-chave: dc.subjectAnions-
Palavras-chave: dc.subjectBasic catalysis-
Palavras-chave: dc.subjectCTA-MCM-41-
Palavras-chave: dc.subjectMicelles-
Palavras-chave: dc.subjectSilicas-
Título: dc.titleInfluence of anions on the structural and catalytic properties of CTA-MCM-41-
Tipo de arquivo: dc.typelivro digital-
Aparece nas coleções:Repositório Institucional - Unesp

Não existem arquivos associados a este item.