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Yuxi L, Peng L, Jun Z, Can W, Longwen C, Dengfeng Y, Quanming R, Xiaoliang L, Mingli F, Suib SL, Daiqi Y. Electrospun Ce-Mn oxide as an efficient catalyst for soot combustion: Ce-Mn synergy, soot-catalyst contact, and catalytic oxidation mechanism. CHEMOSPHERE 2023; 334:138995. [PMID: 37211160 DOI: 10.1016/j.chemosphere.2023.138995] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/23/2023]
Abstract
Increasing the contact efficiency and improving the intrinsic activity are two effective strategies to obtain efficient catalysts for soot combustion. Herein, the electrospinning method is used to synthesize fiber-like Ce-Mn oxide with a strong synergistic effect. The slow combustion of PVP in precursors and highly soluble manganese acetate in spinning solution facilitates the formation of fibrous Ce-Mn oxides. The fluid simulation clearly indicates that the slender and uniform fibers provide more interwoven macropores to capture soot particles than the cubes and spheres do. Accordingly, electrospun Ce-Mn oxide exhibits better catalytic activity than reference catalysts, including Ce-Mn oxides by co-precipitation and sol-gel methods. The characterizations suggest that Mn3+ substitution into fluorite-type CeO2 enhances the reducibility through the acceleration of Mn-Ce electron transfer, improves the lattice oxygen mobility by weakening the Ce-O bonds, and induces oxygen vacancies for the activation of O2. The theoretical calculation reveals that the release of lattice oxygen becomes easy because of a low formation energy of oxygen vacancy, while the high reduction potential is beneficial for the activation of O2 on Ce3+-Ov (oxygen vacancies). Due to above Ce-Mn synergy, the CeMnOx-ES shows more active oxygen species and higher oxygen storage capacity than CeO2-ES and MnOx-ES. The theoretical calculation and experimental results suggest that the adsorbed O2 is more active than lattice oxygen and the catalytic oxidation mainly follows the Langmuir-Hinshelwood mechanism. This study indicates that electrospinning is a novel method to obtain efficient Ce-Mn oxide.
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Affiliation(s)
- Liao Yuxi
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China
| | - Liu Peng
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou, 510006, PR China.
| | - Zhang Jun
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China
| | - Wang Can
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China
| | - Chen Longwen
- College of Light Chemical Industry and Materials Engineering, Shunde Polytechnic, Foshan, 528333, PR China
| | - Yan Dengfeng
- Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou, 510399, PR China
| | - Ren Quanming
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou, 510006, PR China
| | - Liang Xiaoliang
- CAS Key Laboratory of Mineralogy and Metallogeny, Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Fu Mingli
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou, 510006, PR China
| | - Steven L Suib
- Department of Chemistry, University of Connecticut, Storrs, Connecticut, 06269, USA
| | - Ye Daiqi
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou, 510006, PR China.
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