Optimization of the synthesis of SAPO-11 for the methylation of naphthalene with methanol by varying templates and template content

Journal of the Brazilian Chemical Society

Xiaoxiao Wang²  Wei Zhang²  Shaoqing Guo¹  Liangfu Zhao²  Hongwei Xiang² 

[1] ,Chinese Academy of Sciences Institute of Coal Chemistry Taiyuan,People's Republic of China

关键词: SAPO-11;    templates;    template content;    methylation of naphthalene;   

DOI  :  10.5935/0103-5053.20130152

来源: SciELO

【 摘 要 】

SAPO-11 zeolites were successfully synthesized by using three different templates (diethylamine (DEA), di-n-propylamine (DPA) and di-isopropylamine (DIPA)) and varying DPA contents (nDPA/Al2O3 = 0.8, 1.2, 1.6 and 2.0) under hydrothermal conditions. The samples were characterized by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption, temperature programmed desorption of ammonia (NH3-TPD) and29 Si magic angle spinning (MAS) nuclear magnetic resonance (NMR). The samples were also evaluated towards the methylation of naphthalene with methanol to produce 2,6-dimethylnaphthalene (2,6-DMN). XRD results indicated that the directing effect of the different templates for AEL (Aluminophosphate-ELeven) structure decreased in the order DPA > DEA > DIPA and the most suitable DPA content was nDPA/Al2O3 = 1.2. N2 adsorption-desorption results showed that SAPO-11(DPA,1.2) exhibited the broadest pore size distribution, the highest BET specific surface area and the largest pore volume among all the SAPO-11 samples. SAPO-11(DPA,1.2) exhibited high catalytic performances in the methylation of naphthalene due to its high crystallinity, high external surface and broad pore size distribution. The pore structure of SAPO-11 zeolite, rather than its acidity, played an important role in achieving high catalytic performances in the methylation of naphthalene with methanol.

【 授权许可】

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