Volume 62, Issue 29 e202306261
Research Article

Efficient Selective Oxidation of Aromatic Alkanes by Double Cobalt Active Sites over Oxygen Vacancy-rich Mesoporous Co3O4

Yali Liu

Yali Liu

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, Jilin, 130012 China

Department of Chemical Engineering, School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan, Zhejiang, 316022 China

These authors contributed equally to this work.

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Yuenan Zheng

Yuenan Zheng

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, Jilin, 130012 China

State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning, 116081 China

These authors contributed equally to this work.

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Danyang Feng

Danyang Feng

Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Jilin, 130024 China

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Liangliang Zhang

Liangliang Zhang

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, Jilin, 130012 China

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Ling Zhang

Ling Zhang

State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012 China

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Xiaowei Song

Xiaowei Song

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, Jilin, 130012 China

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Prof. Zhen-An Qiao

Corresponding Author

Prof. Zhen-An Qiao

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, Jilin, 130012 China

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First published: 24 May 2023
Citations: 30

Graphical Abstract

Oxygen vacancy-rich mesoporous Co3O4 (mCo3O4) was synthesized by a simple ligand-assisted self-assembly method. Benefitting from abundant oxygen vacancies and the mesoporous structure of mCo3O4, a unique catalytic path was presented with direct oxidation of aromatic alkanes to aromatic ketones rather than the conventional stepwise oxidation to alcohols and then to ketones.

Abstract

The development of efficient catalyst for selective oxidation of hydrocarbon to functional compounds remains a challenge. Herein, mesoporous Co3O4 (mCo3O4-350) showed excellent catalytic activity for selective oxidation of aromatic-alkanes, especially for oxidation of ethylbenzene with a conversion of 42 % and selectivity of 90 % for acetophenone at 120 °C. Notably, mCo3O4 presented a unique catalytic path of direct oxidation of aromatic-alkanes to aromatic ketones rather than the conventional stepwise oxidation to alcohols and then to ketones. Density functional theory calculations revealed that oxygen vacancies in mCo3O4 activate around Co atoms, causing electronic state change from Co3+(Oh)→Co2+(Oh). Co2+(Oh) has great attraction to ethylbenzene, and weak interaction with O2, which provide insufficient O2 for gradual oxidation of phenylethanol to acetophenone. Combined with high energy barrier for forming phenylethanol, the direct oxidation path from ethylbenzene to acetophenone is kinetically favorable on mCo3O4, sharply contrasted to non-selective oxidation of ethylbenzene on commercial Co3O4.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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