Tailoring the accessibility and amphiphilicity of MWW zeolites for two-phase glycerol ketalization

Autor(es)

Lima, Diego S. D. ; Silva, Laura L. L. ; Zapelini, Iago W. W. ; Mintova, Svetlana ; Martins, Leandro

• Tipo de documento: Artigo Científico
• Fonte: INORGANIC CHEMISTRY FRONTIERS; v. 10, n. 19, p. 13-pg., 2023-08-23.

Resumo

Two MWW zeolite catalysts, purely microporous MCM-22 (3D) and hierarchical ITQ-2 (2D), were synthesized and functionalized with dodecyltriethoxysilane. The functionalized zeolites were employed in a two-phase glycerol ketalization reaction with acetone. There are two crucial factors to consider in this reaction: (i) the kinetic diameter of glycerol is comparable to the size of catalyst pores, limiting its accessibility to the active sites and (ii) glycerol exhibits poor solubility in acetone, causing the reaction to predominantly occur at the interfaces. Therefore, it is essential to focus on enhancing the accessibility of chemicals to the inner catalyst pores and adjusting the hydrophilic-hydrophobic balance of the functionalized catalysts to improve the reaction performance. The accessibility of the catalysts was indirectly evaluated by the chemisorption of pyridine and 2,6-di-tert-butylpyridine, which confirmed that ITQ-2 had a superior capacity to accommodate bulkier chemicals. Moreover, contact angle measurements of glycerol on ITQ-2 zeolites indicated that the functionalized materials exhibited reduced interaction with glycerol due to their increased hydrophobic nature. As a result, the functionalized materials tended to accumulate in the interfacial region, facilitating the dispersion of glycerol droplets within the reaction medium and eliminating the need for an additional solvent to homogenize the system. However, the hydrophobic characteristic played a more significant role at the beginning of the reaction since, after reaching 25% conversion, the system transitioned into a single phase as the product acted as a solvent. (AU)

• Processo FAPESP: 17/21965-5 - Síntese e avaliação catalítica de zeolitas embrionárias contendo sítios ácidos ou básicos
• Beneficiário: Laura Lorena da Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 22/01789-6 - Catalisadores zeolíticos lamelares e anfifílicos para reações com moléculas volumosas em sistemas imiscíveis
• Beneficiário: Diego Sarmento Duncan Lima
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 21/08326-9 - Efeitos da cristalinidade e de diferentes aminas na propriedade catalítica ácido-base de H-aluminossilicatos com aminas ancoradas
• Beneficiário: Iago William Zapelini
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 18/01258-5 - Novos processos catalíticos e fotocatalíticos para a conversão direta de metano e CO2 em produtos
• Beneficiário: José Maria Correa Bueno
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 19/12486-1 - EMU concedido no processo 2018/01258-5: cromatógrafo a gás
• Beneficiário: Leandro Pierroni Martins
• Modalidade de apoio: Auxílio à Pesquisa - Programa Equipamentos Multiusuários