Oxidative desulfurization of model oil over Ta-Beta zeolite synthesized via structural reconstruction.
J Hazard Mater
; 393: 122458, 2020 Jul 05.
Article
em En
| MEDLINE
| ID: mdl-32155526
ABSTRACT
As to metallosilicate zeolites, ions with larger size such as Ta5+ in the gels greatly retarded their crystallization during the hydrothermal synthesis, affording long-winded synthesis periods, up-limited framework-substituted metal contents, or even frustrated outcome. An efficient hydrothermal synthesis strategy for metallosilicate, in this case of Ta framework-substituted *BEA zeolite, via structural reconstruction was proposed to stride the gap. The Ta content in our developed Ta-Beta-Re-50 zeolite achieved up to 5.48 % (Si/Ta = 52), breaking through the limitation of Ta contents for conventional method (Si/Ta > 100). Additionally, this Ta-Beta-Re zeolite possessed nanosized crystals (20-40 nm) and short crystallization time (8 h), significantly improving space-time yields of practical zeolite production. Through spectroscopic study, it was confirmed that the existence of zeolite structural units intensively facilitated the formation of nucleation and crystal growth. This innovative Ta-Beta zeolite demonstrated high catalytic performances for oxidation desulfurization, far outperforming traditional fluoride-mediated Ta-Beta-F, which was ascribed to its excellent diffusion properties and incredible high isolated Ta contents. Additionally, the catalytic performance of Ta-Beta-Re could be regenerated after simple calcination and the deactivation may be caused by pore blocking of organics. This work provides a new method for rationally design and construction of metallosilicate materials with high activity for catalytic oxidation applications, which can bridge the conceptual and technical gap between periodic trends and zeolite material synthesis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Hazard Mater
Assunto da revista:
SAUDE AMBIENTAL
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
China