Journal
MICROPOROUS AND MESOPOROUS MATERIALS
Volume 121, Issue 1-3, Pages 185-193Publisher
ELSEVIER
DOI: 10.1016/j.micromeso.2009.01.030
Keywords
Ordered hexagonal mesostructure; Zr-SBA-15; Hydrothermal stability; Sulfation; Esterification and transesterification
Categories
Funding
- State Basic Research Project of China [2009CB623507]
- National Natural Science Foundation of China [20773049]
Ask authors/readers for more resources
Ordered hexagonal mesoporous Zr-SBA-15(x)s (where x stands for Si/Zr) with a large amount of zirconium heteroatoms (Si/Zr at 5.0-9.0) have been successfully synthesized under the assistance of urea by using tri-block copolymer as a template. The results obtained from XRD and N-2 isotherm techniques indicate that these Zr-SBA-15s have more excellent hydrothermal stabilities in both boiling water and 100% steaming than SBA-15 does. UV-vis spectroscopy suggests that zirconium species are mainly amorphous zirconia in Zr-SBA-15(4) and Zr-SBA-15(5), while they are highly isolated Zr4+ ion in Zr-SBA-15(7) and Zr-SBA-15(9). After sulfation, Zr-SBA-15(7) and Zr-SBA-15(9) basically maintain their ordered hexagonal mesostructure and isolated Zr4+ ion. Catalytic tests in esterification and transesterification show that sulfated Zr-SBA-15(7) and Zr-SBA-15(9) with isolated Zr4+ exhibit much higher catalytic activities than sulfated Zr-SBA-15(4) and Zr-SBA-15(5) with amorphous zirconia, indicating that the isolated Zr4+ species are more favorable for the formation of acidic sites than amorphous zirconia. The sulfation of isolated Zr4+ species in porous silica materials with large surface area may offer a novel route for preparation of good acidic catalysts in the future. (C) 2009 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available