Effect of different seed sources on the hydrothermal crystallization of MCM-22 zeolite catalysts

Autor(es)

Rodrigues, Mariana V. ^[1] ; Vieira, Luiz H. ^[1] ; Campos, Guilherme P. ^[1] ; Martins, Leandro ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Inst Quim, Campus Araraquara, Rua Prof Francisco Degni 55, BR-14800900 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CrystEngComm; v. 20, n. 25, p. 3467-3475, JUL 7 2018.
• Citações Web of Science: 1

Resumo

Zeolites are solid acids with several industrial applications, but usually their syntheses are difficult or costly and this negatively interferes in their use as catalysts or adsorbents. A seed-assisted approach is an alternative route to facilitating zeolite synthesis, shortening crystallization time, allowing template-free synthesis and decreasing costs and is environmentally friendly. In this study, the seed-assisted synthesis was applied to the MCM-22 zeolite. Three types of seeds were studied: the MCM-22, the ball milled MCM-22 and the micro-seeds in the mother liquor from an unseeded synthesis. XRD studies showed successful zeolite crystallization in shorter times, and SEM images pointed out a decrease in the crystal size, with the ball milled seed giving the best results. In the presence of seeds, the organic template was reduced up to 50%, but contamination with zeolite ZSM-5 was detected. The template-free synthesis did not lead to crystallization because in the synthesis of low Si/Al ratio zeolites, the interaction between aluminum and the template is needed for zeolite nucleation, as revealed by carbon and aluminum NMR. Due to the decrease in the crystal size, the seed-synthesized zeolites had an improved catalytic performance in liquid-phase glycerol condensation with acetone. (AU)

• Processo FAPESP: 14/20116-6 - Desenvolvimento e aplicação de vanadossilicatos lamelares como catalisadores na desidratação oxidativa do glicerol
• Beneficiário: Luiz Henrique Vieira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/01328-0 - Metodologias avançadas de síntese de zeólitas hierárquicas e caracterização por diferentes técnicas para melhor utilização de materiais microporosos em catálise heterogênea
• Beneficiário: Leandro Pierroni Martins
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/14938-0 - Controle da cinética de cristalização de catalisadores zeolíticos lamelares por adição de sementes
• Beneficiário: Guilherme Pires de Campos
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 14/12942-3 - Combinação de química supramolecular e emulsões na síntese de catalisadores lamelares esfoliados
• Beneficiário: Mariana Veiga Rodrigues
• Modalidade de apoio: Bolsas no Brasil - Doutorado