Catalytically active and hierarchically porous SAPO-11 zeolite synthesized in the presence of polyhexamethylene biguanidine

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• 作者：Yan Liu ; Wei Qu ; Weiwei Chang ; Shuxiang Pan ; Zhijian Tian ; Xiangju Meng ; Marcello Rigutto ; Alex ; er van der Made ; Lan Zhao ; Xiaoming Zheng ; Feng-Shou Xiao
• 关键词：Hierarchical zeolite ; SAPO-11 ; Supported platinum catalyst ; Hydroisomerization ; n-Dodecane
• 刊名：Journal of Colloid and Interface Science
• 出版年：15 March, 2014
• 年：2014
• 卷：418
• 期：Complete
• 页码：193-199
• 全文大小：2230 K

文摘

Hierarchically porous SAPO-11 zeolite (H-SAPO-11) is rationally synthesized from a starting silicoaluminophosphate gel in the presence of polyhexamethylene biguanidine as a mesoscale template. The sample is well characterized by XRD, N₂ sorption, SEM, TEM, NMR, XPS, NH₃-TPD, and TG techniques. The results show that the sample obtained has good crystallinity, hierarchical porosity (mesopores at ca. 10 nm and macropores at ca. 50-200 nm), high BET surface area (226 m²/g), large pore volume (0.25 cm³/g), and abundant medium and strong acidic sites (0.36 mmol/g). After loading Pt (0.5 wt.%) on H-SAPO-11 by using wet impregnation method, catalytic hydroisomerization tests of n-dodecane show that the hierarchical Pt/SAPO-11 zeolite exhibits high conversion of n-dodecane and enhanced selectivity for branched products as well as reduced selectivity for cracking products, compared with conventional Pt/SAPO-11 zeolite. This phenomenon is reasonably attributed to the presence of hierarchical porosity, which is favorable for access of reactants on catalytically active sites. The improvement in catalytic performance in long-chain paraffin hydroisomerization over Pt/SAPO-11-based catalyst is of great importance for its industrial applications in the future.