Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5357644 | Applied Surface Science | 2010 | 6 Pages |
Abstract
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 μmol/g).
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Xinyu Chen, Min Jia, Guozhu Liu, Xiangwen Zhang, Li Wang, Zhentao Mi,