| Texto completo | |
| Autor(es): |
Pereira, Elen M. F.
;
Zapelini, Iago W.
;
Silva, Eliane S.
;
Urquieta-Gonzalez, Ernesto A.
;
Martins, Leandro
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | FUEL; v. 406, p. 9-pg., 2025-10-22. |
| Resumo | |
Coke formation in zeolites is typically adverse, leading to catalyst deactivation. However, this study explores the intentional coking of SSZ-13 catalysts to enhance their performance in the methanol-to-olefins (MTO) reaction by incorporating a small amount (1.6 wt%) of a selected family of coke, which is more active in the MTO. During MTO, polyaromatic hydrocarbons (PAH) form within the zeolite pores, playing a crucial role in the MTO mechanism. While excessive polymerization deactivates the catalyst, smaller PAH species promote olefin production. Here, coke formation was induced with toluene to regulate MTO through the production of PAH. Although this strategy led to a higher initial activity compared to the pristine catalyst, the total coke content continued to grow with reaction time. Nevertheless, the coked catalyst (SSZ-13-C) exhibited an initially slower PAH accumulation rate than the pristine catalyst, leading to reduced deactivation. Small amounts of oxygenated species were detected at the early stages of the reaction, indicating interactions with the zeolite's acid sites, which modulate acidity and modify the MTO dynamics. To enhance the formation of oxygenates and improve performance, CO2 was added as a mild oxidizing agent for PAH, resulting in a 10% increase in olefin selectivity. Operando UV-Vis spectroscopy revealed a delay in the initial growth of PAH, while chromatography-mass spectrometry confirmed an accelerated and progressive evolution of coke species over time. (AU) | |
| Processo FAPESP: | 21/12394-0 - Métodos sintéticos sustentáveis empregando catálise, solventes verdes, reagentes seguros e materiais de partida renováveis |
| Beneficiário: | Arlene Gonçalves Corrêa |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 23/10544-0 - Melhoria simultânea da acessibilidade e hidrofobicidade em zeólitas: cristais nanométricos tolerantes à água do meio reacional |
| Beneficiário: | Leandro Pierroni Martins |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 23/01953-3 - Materiais aplicados na transformação de biomassa em diesel verde: do laboratório ao piloto |
| Beneficiário: | Sandra Helena Pulcinelli |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa BIOEN - 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 |