Effect of the SiO2/TiO2 ratio on the solid acidity of SiO2-TiO2/montmorillonite composites

Yoshikazu Kameshima; Tomohisa Koike; Toshihiro Isobe; Akira Nakajima; Kiyoshi Okada

doi:10.1016/j.materresbull.2009.05.005

Effect of the SiO₂/TiO₂ ratio on the solid acidity of SiO₂-TiO₂/montmorillonite composites

Yoshikazu Kameshima, Tomohisa Koike, Toshihiro Isobe, Akira Nakajima, Kiyoshi Okada

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

SiO₂-TiO₂/montmorillonite composites with varying SiO₂/TiO₂ molar ratios were synthesized and the effect of the SiO₂/TiO₂ ratio on the solid acidity of the resulting composites was investigated. Four composites with SiO₂/TiO₂ molar ratios of 0, 0.1, 1 and 10 were synthesized by the reaction of colloidal SiO₂-TiO₂ particles prepared from alkoxides with sodium-montmorillonite at room temperature. The composites showed slight expansion and broadening of the XRD basal reflection, corresponding to the intercalation of fine colloidal SiO₂-TiO₂ particles into the montmorillonite sheets and incomplete intercalation to form disordered stacking of exfoliated montmorillonite and colloidal SiO₂-TiO₂ particles. The colloidal particles crystallized to anatase in the low SiO₂/TiO₂ composites but remained amorphous in the high SiO₂/TiO₂ composites. The specific surface areas (S_BET) of the composites measured by N₂ adsorption ranged from 250 to 370 m²/g, considerably greater than in montmorillonite (6 m²/g). The pore size increased with decreasing SiO₂/TiO₂ molar ratio of the composites. The NH₃-TPD spectra of the composites consisted of overlapping peaks, corresponded to temperatures of about 190 and 290 °C. The amounts of solid acid obtained from NH₃-TPD were 186-338 μmol/g in the composites; these values are higher than in the commercial catalyst K10 (85 μmol/g), which is synthesized by acid-treatment of montmorillonite. The present sample with SiO₂/TiO₂ = 0.1 showed the highest amount of acid, about four times higher than K10.

Original language	English
Pages (from-to)	1906-1909
Number of pages	4
Journal	Materials Research Bulletin
Volume	44
Issue number	9
DOIs	https://doi.org/10.1016/j.materresbull.2009.05.005
Publication status	Published - Sept 2009
Externally published	Yes

Keywords

A. Composites
A. Layered compounds
B. Intercalation reactions
D. Surface properties

ASJC Scopus subject areas

Materials Science(all)
Condensed Matter Physics
Mechanics of Materials
Mechanical Engineering

Access to Document

10.1016/j.materresbull.2009.05.005

Cite this

@article{6c9d7126816d41ee9cef9466bb0736f1,

title = "Effect of the SiO2/TiO2 ratio on the solid acidity of SiO2-TiO2/montmorillonite composites",

abstract = "SiO2-TiO2/montmorillonite composites with varying SiO2/TiO2 molar ratios were synthesized and the effect of the SiO2/TiO2 ratio on the solid acidity of the resulting composites was investigated. Four composites with SiO2/TiO2 molar ratios of 0, 0.1, 1 and 10 were synthesized by the reaction of colloidal SiO2-TiO2 particles prepared from alkoxides with sodium-montmorillonite at room temperature. The composites showed slight expansion and broadening of the XRD basal reflection, corresponding to the intercalation of fine colloidal SiO2-TiO2 particles into the montmorillonite sheets and incomplete intercalation to form disordered stacking of exfoliated montmorillonite and colloidal SiO2-TiO2 particles. The colloidal particles crystallized to anatase in the low SiO2/TiO2 composites but remained amorphous in the high SiO2/TiO2 composites. The specific surface areas (SBET) of the composites measured by N2 adsorption ranged from 250 to 370 m2/g, considerably greater than in montmorillonite (6 m2/g). The pore size increased with decreasing SiO2/TiO2 molar ratio of the composites. The NH3-TPD spectra of the composites consisted of overlapping peaks, corresponded to temperatures of about 190 and 290 °C. The amounts of solid acid obtained from NH3-TPD were 186-338 μmol/g in the composites; these values are higher than in the commercial catalyst K10 (85 μmol/g), which is synthesized by acid-treatment of montmorillonite. The present sample with SiO2/TiO2 = 0.1 showed the highest amount of acid, about four times higher than K10.",

keywords = "A. Composites, A. Layered compounds, B. Intercalation reactions, D. Surface properties",

author = "Yoshikazu Kameshima and Tomohisa Koike and Toshihiro Isobe and Akira Nakajima and Kiyoshi Okada",

year = "2009",

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doi = "10.1016/j.materresbull.2009.05.005",

language = "English",

volume = "44",

pages = "1906--1909",

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T1 - Effect of the SiO2/TiO2 ratio on the solid acidity of SiO2-TiO2/montmorillonite composites

AU - Kameshima, Yoshikazu

AU - Koike, Tomohisa

AU - Isobe, Toshihiro

AU - Nakajima, Akira

AU - Okada, Kiyoshi

PY - 2009/9

Y1 - 2009/9

N2 - SiO2-TiO2/montmorillonite composites with varying SiO2/TiO2 molar ratios were synthesized and the effect of the SiO2/TiO2 ratio on the solid acidity of the resulting composites was investigated. Four composites with SiO2/TiO2 molar ratios of 0, 0.1, 1 and 10 were synthesized by the reaction of colloidal SiO2-TiO2 particles prepared from alkoxides with sodium-montmorillonite at room temperature. The composites showed slight expansion and broadening of the XRD basal reflection, corresponding to the intercalation of fine colloidal SiO2-TiO2 particles into the montmorillonite sheets and incomplete intercalation to form disordered stacking of exfoliated montmorillonite and colloidal SiO2-TiO2 particles. The colloidal particles crystallized to anatase in the low SiO2/TiO2 composites but remained amorphous in the high SiO2/TiO2 composites. The specific surface areas (SBET) of the composites measured by N2 adsorption ranged from 250 to 370 m2/g, considerably greater than in montmorillonite (6 m2/g). The pore size increased with decreasing SiO2/TiO2 molar ratio of the composites. The NH3-TPD spectra of the composites consisted of overlapping peaks, corresponded to temperatures of about 190 and 290 °C. The amounts of solid acid obtained from NH3-TPD were 186-338 μmol/g in the composites; these values are higher than in the commercial catalyst K10 (85 μmol/g), which is synthesized by acid-treatment of montmorillonite. The present sample with SiO2/TiO2 = 0.1 showed the highest amount of acid, about four times higher than K10.

AB - SiO2-TiO2/montmorillonite composites with varying SiO2/TiO2 molar ratios were synthesized and the effect of the SiO2/TiO2 ratio on the solid acidity of the resulting composites was investigated. Four composites with SiO2/TiO2 molar ratios of 0, 0.1, 1 and 10 were synthesized by the reaction of colloidal SiO2-TiO2 particles prepared from alkoxides with sodium-montmorillonite at room temperature. The composites showed slight expansion and broadening of the XRD basal reflection, corresponding to the intercalation of fine colloidal SiO2-TiO2 particles into the montmorillonite sheets and incomplete intercalation to form disordered stacking of exfoliated montmorillonite and colloidal SiO2-TiO2 particles. The colloidal particles crystallized to anatase in the low SiO2/TiO2 composites but remained amorphous in the high SiO2/TiO2 composites. The specific surface areas (SBET) of the composites measured by N2 adsorption ranged from 250 to 370 m2/g, considerably greater than in montmorillonite (6 m2/g). The pore size increased with decreasing SiO2/TiO2 molar ratio of the composites. The NH3-TPD spectra of the composites consisted of overlapping peaks, corresponded to temperatures of about 190 and 290 °C. The amounts of solid acid obtained from NH3-TPD were 186-338 μmol/g in the composites; these values are higher than in the commercial catalyst K10 (85 μmol/g), which is synthesized by acid-treatment of montmorillonite. The present sample with SiO2/TiO2 = 0.1 showed the highest amount of acid, about four times higher than K10.

KW - A. Composites

KW - A. Layered compounds

KW - B. Intercalation reactions

KW - D. Surface properties

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SN - 0025-5408

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