Synthesis and characterization of mesoporous Ta-W oxides as strong solid acid catalysts

Caio Tagusagawa; Atsushi Takagaki; Ai Iguchi; Kazuhiro Takanabe; Junko N. Kondo; Kohki Ebitani; Takashi Tatsumi; Kazunari Domen

doi:10.1021/cm903767n

Synthesis and characterization of mesoporous Ta-W oxides as strong solid acid catalysts

Caio Tagusagawa, Atsushi Takagaki, Ai Iguchi, Kazuhiro Takanabe, Junko N. Kondo, Kohki Ebitani, Takashi Tatsumi, Kazunari Domen^*

^*Corresponding author for this work

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

56 Scopus citations

Abstract

Several mesoporous Ta_xW_10-x mixed oxides prepared from TaCl₅ and WCl₆ in the presence of poly block copolymer surfactant Pluronic P-123 were examined as potential solid acid catalysts. Amorphous wormhole-type mesopores were observed in samples with x values from 3 to 10, whereas W-rich samples (x = 0-2) formed nonmesoporous structures with crystallized tungsten oxide (WO₃). The acid strength increased with addition of W for mesoporous Ta_xW_10-x oxides, and mesoporous Ta₃W₇ oxide exhibited the highest acid catalytic activity for the Friedel-Crafts alkylation of anisole and the hydrolysis of disaccharides. The results are compared with those of nonporous Ta₂O₅-WO₃, HTaWO₆ nanosheets, which were a solid acid obtained by exfoliation and aggregation of layered HTaWO ₆ with strong Brønsted acid sites in the interlayer, and a range of conventional solid acid catalysts. Mesoporous Ta-W oxides exhibited a turnover rate higher than that of nonporous Ta₂O₅-WO ₃ and HTaWO₆ nanosheets, indicating that the mesoporous structure is an advantageous environment for the strong acid sites, because of the high surface area and easy reactant accessibility.

Original language	English (US)
Pages (from-to)	3072-3078
Number of pages	7
Journal	Chemistry of Materials
Volume	22
Issue number	10
DOIs	https://doi.org/10.1021/cm903767n
State	Published - May 25 2010
Externally published	Yes

ASJC Scopus subject areas

General Chemistry
General Chemical Engineering
Materials Chemistry

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title = "Synthesis and characterization of mesoporous Ta-W oxides as strong solid acid catalysts",

abstract = "Several mesoporous TaxW10-x mixed oxides prepared from TaCl5 and WCl6 in the presence of poly block copolymer surfactant Pluronic P-123 were examined as potential solid acid catalysts. Amorphous wormhole-type mesopores were observed in samples with x values from 3 to 10, whereas W-rich samples (x = 0-2) formed nonmesoporous structures with crystallized tungsten oxide (WO3). The acid strength increased with addition of W for mesoporous TaxW10-x oxides, and mesoporous Ta3W7 oxide exhibited the highest acid catalytic activity for the Friedel-Crafts alkylation of anisole and the hydrolysis of disaccharides. The results are compared with those of nonporous Ta2O5-WO3, HTaWO6 nanosheets, which were a solid acid obtained by exfoliation and aggregation of layered HTaWO 6 with strong Br{\o}nsted acid sites in the interlayer, and a range of conventional solid acid catalysts. Mesoporous Ta-W oxides exhibited a turnover rate higher than that of nonporous Ta2O5-WO 3 and HTaWO6 nanosheets, indicating that the mesoporous structure is an advantageous environment for the strong acid sites, because of the high surface area and easy reactant accessibility.",

author = "Caio Tagusagawa and Atsushi Takagaki and Ai Iguchi and Kazuhiro Takanabe and Kondo, {Junko N.} and Kohki Ebitani and Takashi Tatsumi and Kazunari Domen",

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doi = "10.1021/cm903767n",

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T1 - Synthesis and characterization of mesoporous Ta-W oxides as strong solid acid catalysts

AU - Tagusagawa, Caio

AU - Takagaki, Atsushi

AU - Iguchi, Ai

AU - Takanabe, Kazuhiro

AU - Kondo, Junko N.

AU - Ebitani, Kohki

AU - Tatsumi, Takashi

AU - Domen, Kazunari

PY - 2010/5/25

Y1 - 2010/5/25

N2 - Several mesoporous TaxW10-x mixed oxides prepared from TaCl5 and WCl6 in the presence of poly block copolymer surfactant Pluronic P-123 were examined as potential solid acid catalysts. Amorphous wormhole-type mesopores were observed in samples with x values from 3 to 10, whereas W-rich samples (x = 0-2) formed nonmesoporous structures with crystallized tungsten oxide (WO3). The acid strength increased with addition of W for mesoporous TaxW10-x oxides, and mesoporous Ta3W7 oxide exhibited the highest acid catalytic activity for the Friedel-Crafts alkylation of anisole and the hydrolysis of disaccharides. The results are compared with those of nonporous Ta2O5-WO3, HTaWO6 nanosheets, which were a solid acid obtained by exfoliation and aggregation of layered HTaWO 6 with strong Brønsted acid sites in the interlayer, and a range of conventional solid acid catalysts. Mesoporous Ta-W oxides exhibited a turnover rate higher than that of nonporous Ta2O5-WO 3 and HTaWO6 nanosheets, indicating that the mesoporous structure is an advantageous environment for the strong acid sites, because of the high surface area and easy reactant accessibility.

AB - Several mesoporous TaxW10-x mixed oxides prepared from TaCl5 and WCl6 in the presence of poly block copolymer surfactant Pluronic P-123 were examined as potential solid acid catalysts. Amorphous wormhole-type mesopores were observed in samples with x values from 3 to 10, whereas W-rich samples (x = 0-2) formed nonmesoporous structures with crystallized tungsten oxide (WO3). The acid strength increased with addition of W for mesoporous TaxW10-x oxides, and mesoporous Ta3W7 oxide exhibited the highest acid catalytic activity for the Friedel-Crafts alkylation of anisole and the hydrolysis of disaccharides. The results are compared with those of nonporous Ta2O5-WO3, HTaWO6 nanosheets, which were a solid acid obtained by exfoliation and aggregation of layered HTaWO 6 with strong Brønsted acid sites in the interlayer, and a range of conventional solid acid catalysts. Mesoporous Ta-W oxides exhibited a turnover rate higher than that of nonporous Ta2O5-WO 3 and HTaWO6 nanosheets, indicating that the mesoporous structure is an advantageous environment for the strong acid sites, because of the high surface area and easy reactant accessibility.

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Synthesis and characterization of mesoporous Ta-W oxides as strong solid acid catalysts

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