Indexed by:
Journal Papers
First Author:
Wang, Xinyang
Correspondence Author:
Li, XY (reprint author), Dalian Univ Technol, Sch Environm Sci & Technol, Key Lab Ind Ecol & Environm Engn MOE, State Key Lab Fine Chem, Dalian 116024, Peoples R China.; Li, XY (reprint author), Curtin Univ, Dept Chem Engn, GPO Box U1987, Perth, WA 6845, Australia.
Co-author:
Li, Xinyong,Mu, Jincheng,Fan, Shiying,Chen, Xin,Wang, Liang,Yin, Zhifan,Tade, Moses,Liu, Shaomin
Date of Publication:
2019-11-13
Journal:
ACS APPLIED MATERIALS & INTERFACES
Included Journals:
PubMed、EI、SCIE
Document Type:
J
Volume:
11
Issue:
45
Page Number:
41988-41999
ISSN No.:
1944-8244
Key Words:
Co3O4 nanosheets; surface oxygen vacancy; facile surface reduction; NO
reduction by CO; CO oxidation
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 O-2-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 degrees C in NO reduction by CO and 100% CO conversion at 100 degrees 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.
Translation or Not:
no
