Aerobic oxidation of toluene and benzyl alcohol to benzaldehyde using a visible light-responsive titanium-oxide cluster

Wenli Wu; Guanyun Zhang; Jian Zhang; Guo Wang; Chen Ho Tung; Yifeng Wang

doi:10.1016/j.cej.2020.126433

Aerobic oxidation of toluene and benzyl alcohol to benzaldehyde using a visible light-responsive titanium-oxide cluster

Wenli Wu, Guanyun Zhang, Jian Zhang, Guo Wang, Chen Ho Tung, Yifeng Wang

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

32 Scopus citations

Abstract

Photocatalytic selective oxidation using sunlight and O₂ can serve as a green and cost-effective method for the transformation of organic raw materials to value-added products. Here, we report a [Ti₆O₈(OH₂)₂₀]⁸⁺ cluster modified with Br^– (denoted as Ti₆B) triggers the selective conversion of toluene and benzyl alcohol to benzaldehyde under visible light irradiation with high efficiency. The absorption edge of Ti₆B in MeCN solution is ca. 500 nm. The conversion of toluene, operated under non-solvent conditions, reached 4.7% with ca. 80% selectivity. The yield of benzaldehyde from benzyl alcohol reached 96%. Common substituents could be tolerated. ESR analyses indicate superoxide is directly involved in the reactions. The results of ¹⁷O NMR, IR and small angle scattering indicate Ti₆B is the true photocatalyst. Mechanistic studies suggest Br^– binds to Ti⁴⁺ at the Ti-oxo core of Ti₆B and the photo-driven electronic transition is from HOMO comprised of Br2p to LUMO + 1 comprised of Ti3d orbitals.

Original language	English
Article number	126433
Journal	Chemical Engineering Journal
Volume	404
DOIs	https://doi.org/10.1016/j.cej.2020.126433
State	Published - 15 Jan 2021
Externally published	Yes

Keywords

Br–association
Photocatalysis
Selective oxidation
Titanium-oxide cluster
Visible light

ASJC Scopus subject areas

General Chemistry
Environmental Chemistry
General Chemical Engineering
Industrial and Manufacturing Engineering

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10.1016/j.cej.2020.126433

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title = "Aerobic oxidation of toluene and benzyl alcohol to benzaldehyde using a visible light-responsive titanium-oxide cluster",

abstract = "Photocatalytic selective oxidation using sunlight and O2 can serve as a green and cost-effective method for the transformation of organic raw materials to value-added products. Here, we report a [Ti6O8(OH2)20]8+ cluster modified with Br– (denoted as Ti6B) triggers the selective conversion of toluene and benzyl alcohol to benzaldehyde under visible light irradiation with high efficiency. The absorption edge of Ti6B in MeCN solution is ca. 500 nm. The conversion of toluene, operated under non-solvent conditions, reached 4.7% with ca. 80% selectivity. The yield of benzaldehyde from benzyl alcohol reached 96%. Common substituents could be tolerated. ESR analyses indicate superoxide is directly involved in the reactions. The results of 17O NMR, IR and small angle scattering indicate Ti6B is the true photocatalyst. Mechanistic studies suggest Br– binds to Ti4+ at the Ti-oxo core of Ti6B and the photo-driven electronic transition is from HOMO comprised of Br2p to LUMO + 1 comprised of Ti3d orbitals.",

keywords = "Br–association, Photocatalysis, Selective oxidation, Titanium-oxide cluster, Visible light",

author = "Wenli Wu and Guanyun Zhang and Jian Zhang and Guo Wang and Tung, {Chen Ho} and Yifeng Wang",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",

year = "2021",

month = jan,

day = "15",

doi = "10.1016/j.cej.2020.126433",

language = "English",

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T1 - Aerobic oxidation of toluene and benzyl alcohol to benzaldehyde using a visible light-responsive titanium-oxide cluster

AU - Wu, Wenli

AU - Zhang, Guanyun

AU - Zhang, Jian

AU - Wang, Guo

AU - Tung, Chen Ho

AU - Wang, Yifeng

PY - 2021/1/15

Y1 - 2021/1/15

N2 - Photocatalytic selective oxidation using sunlight and O2 can serve as a green and cost-effective method for the transformation of organic raw materials to value-added products. Here, we report a [Ti6O8(OH2)20]8+ cluster modified with Br– (denoted as Ti6B) triggers the selective conversion of toluene and benzyl alcohol to benzaldehyde under visible light irradiation with high efficiency. The absorption edge of Ti6B in MeCN solution is ca. 500 nm. The conversion of toluene, operated under non-solvent conditions, reached 4.7% with ca. 80% selectivity. The yield of benzaldehyde from benzyl alcohol reached 96%. Common substituents could be tolerated. ESR analyses indicate superoxide is directly involved in the reactions. The results of 17O NMR, IR and small angle scattering indicate Ti6B is the true photocatalyst. Mechanistic studies suggest Br– binds to Ti4+ at the Ti-oxo core of Ti6B and the photo-driven electronic transition is from HOMO comprised of Br2p to LUMO + 1 comprised of Ti3d orbitals.

AB - Photocatalytic selective oxidation using sunlight and O2 can serve as a green and cost-effective method for the transformation of organic raw materials to value-added products. Here, we report a [Ti6O8(OH2)20]8+ cluster modified with Br– (denoted as Ti6B) triggers the selective conversion of toluene and benzyl alcohol to benzaldehyde under visible light irradiation with high efficiency. The absorption edge of Ti6B in MeCN solution is ca. 500 nm. The conversion of toluene, operated under non-solvent conditions, reached 4.7% with ca. 80% selectivity. The yield of benzaldehyde from benzyl alcohol reached 96%. Common substituents could be tolerated. ESR analyses indicate superoxide is directly involved in the reactions. The results of 17O NMR, IR and small angle scattering indicate Ti6B is the true photocatalyst. Mechanistic studies suggest Br– binds to Ti4+ at the Ti-oxo core of Ti6B and the photo-driven electronic transition is from HOMO comprised of Br2p to LUMO + 1 comprised of Ti3d orbitals.

KW - Br–association

KW - Photocatalysis

KW - Selective oxidation

KW - Titanium-oxide cluster

KW - Visible light

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DO - 10.1016/j.cej.2020.126433

M3 - Article

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SN - 1385-8947

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JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

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ER -

Aerobic oxidation of toluene and benzyl alcohol to benzaldehyde using a visible light-responsive titanium-oxide cluster

Abstract

Keywords

ASJC Scopus subject areas

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