Oxygen Vacancy-rich Porous Co3O4 Nanosheets toward Boosted NO Reduction by CO and CO Oxidation: Insights into the Structure-Activity Relationship and Performance Enhancement Mechanism

Wang, X.; Li, Xinyong; Mu, J.; Fan, S.; Chen, X.; Wang, L.; Yin, Z.; Tade, Moses; Liu, Shaomin

doi:10.1021/acsami.9b08664

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Authors

Wang, X.

Li, Xinyong

Mu, J.

Fan, S.

Chen, X.

Wang, L.

Yin, Z.

Tade, Moses

Liu, Shaomin

Date

2019

Type

Journal Article

Metadata

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Citation

Wang, X. and Li, X. and Mu, J. and Fan, S. and Chen, X. and Wang, L. and Yin, Z. et al. 2019. Oxygen Vacancy-rich Porous Co3O4 Nanosheets toward Boosted NO Reduction by CO and CO Oxidation: Insights into the Structure-Activity Relationship and Performance Enhancement Mechanism. ACS Applied Materials and Interfaces. 11 (45): pp. 41988-41999.

Source Title

ACS Applied Materials and Interfaces

DOI

10.1021/acsami.9b08664

ISSN

1944-8244

Faculty

Faculty of Science and Engineering

School

WASM: Minerals, Energy and Chemical Engineering

URI

http://hdl.handle.net/20.500.11937/79347

Collection

Curtin Research Publications

Abstract

Oxygen vacancy-rich porous Co3O4 nanosheets (OV-Co3O4) with diverse surface oxygen vacancy contents were synthesized via facile surface reduction and applied to NO reduction by CO and CO oxidation. The structure-activity relationship between surface oxygen vacancies and catalytic performance was systematically investigated. By combining Raman, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and O2-temperature programmed desorption, it was found that the efficient surface reduction leads to the presence of more surface oxygen vacancies and thus distinctly enhance the surface oxygen amount and mobility of OV-Co3O4. The electron transfer towards Co sites was promoted by surface oxygen vacancies with higher content. Compared with the pristine porous Co3O4 nanosheets, the presence of more surface oxygen vacancies is beneficial for the catalytic performance enhancement for NO reduction by CO and CO oxidation. The OV-Co3O4 obtained in 0.05 mol L-1 NaBH4 solution (Co3O4-0.05) exhibited the best catalytic activity, achieving 100% NO conversion at 175 °C in NO reduction by CO and 100% CO conversion at 100 °C in CO oxidation, respectively. Co3O4-0.05 exhibited outstanding catalytic stability and resistance to high gas hour space velocity in both reactions. Combining in situ DRIFTS results, the enhanced performance of OV-Co3O4 for NO reduction by CO should be attributed to the promoted formation and transformation of dinitrosyl species and -NCO species at lower and higher temperatures. The enhanced performance of OV-Co3O4 for CO oxidation is due to the promotion of oxygen activation ability, surface oxygen mobility, as well as the enhanced CO2 desorption ability. The results indicate that the direct regulation of surface oxygen vacancies could be an efficient way to evidently enhance the catalytic performance for NO reduction by CO and CO oxidation.