Mesoporous silicas containing carboxylic acid : Preparation, thermal degradation, and catalytic performance

Sumiya Sadanobu

Kubota Yuka

Oumi Yasunori

Sadakane Masahiro

Sano Tsuneji

Applied Catalysis A: general

The calcination and thermal degradation behaviors of surfactants in mesoporous silicas SBA-15 and MCM-41 were investigated by FT-IR, C-13 CP/MAS NMR, TG/DTA, and GPC. It was found that carboxylic acid-containing products were generated as active components in the mesopores of SBA-15 and MCM-41 from the triblock copolymer (PEO)(20)(PPO)(70)(PEO)(20) and cetyltrimethylammonium bromide (CTAB), respectively; the latter materials were used as templates. The carboxylic acid-containing mesoporous silica obtained showed a catalytic activity for hydrolysis of sucrose. The acidity was evaluated by means of NaOH titration. The acidity sensitively depended on both the calcination temperature and the atmosphere; the maximum appeared at 150 degrees C in air for SBA-15 where the highest activity was observed. However, the product in MCM-41 showed a lower catalytic activity than that in SBA-15. The SBA-15 product was easily leached from the mesopores of SBA-15 into the solution, but the degree of leaching for MCM-41 was considerably smaller than that for SBA-15.

Carboxylic acid

Degradation

Surfactant

SBA-15

MCM-41

Sucrose hydrolysis

Chemistry [ 430 ]

eng

Elsevier Science BV

Copyright (c) 2009 Elsevier B.V. All rights reserved.

[ISSN] 0926-860X

[DOI] 10.1016/j.apcata.2009.10.015

[NCID] AA10821202

[DOI] http://dx.doi.org/10.1016/j.apcata.2009.10.015