Catalytic performance of grafted Al-MCM-41 in hydroisomerization of n-dodecane

✍ Scribed by Xinyu Chen; Min Jia; Guozhu Liu; Xiangwen Zhang; Li Wang; Zhentao Mi

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 662 KB
• Volume: 256
• Category: Article
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2010.03.060

✦ Synopsis

Pt/Al-MCM-41 samples with constant metal loading but various Si/Al ratios were prepared by reacting pure silica MCM-41 with different concentrations of polyaluminum chloride (PAC) aqueous solutions. It is observed that the molar ratio of Si/Al decreases from 24.3 to 11.2 when increase the PAC concentration from 0.1 M to 2.0 M. A better retention of structural integrity could be seen when the PAC concentration is below 1.0 M. The Lewis acid increases while incorporating aluminum into the framework of MCM-41, while the Brönsted acid reaches a maximum value when the PAC concentration is 1.0 M. Hydroisomerization of n-dodecane was carried out over these Pt/Al-MCM-41 samples. It is demonstrated that increasing the aluminum content generally can trigger a higher n-dodecane conversion, but a lower isomers selectivity due to the increasing strong Brönsted acid sites. And the Pt/Al-MCM-41 post-synthesized by the PAC concentration at 1.0 M shows highest isomers selectivity and yield corresponding to the maximum medium Brönsted acid quantities (24.15 mol/g).