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Jin C, Si W, Chen Y, Zhao X, Zhou B, Shen Y, Zhu Q, Chu Y, Liu F, Li M, Li J. Enhancing CO catalytic oxidation performance over Cu-doping manganese oxide octahedral molecular sieves catalyst. J Colloid Interface Sci 2024; 663:541-553. [PMID: 38428112 DOI: 10.1016/j.jcis.2024.02.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/25/2024] [Accepted: 02/05/2024] [Indexed: 03/03/2024]
Abstract
The CO oxidation catalytic activity of catalysts is strongly influenced by the oxygen vacancy defects (OVDs) concentration and the valence state of active metal. Herein, a defect engineering approach was implemented to enhance the oxygen vacancy defects and to modify the valence of metal ions in manganese oxide octahedral molecular sieves (OMS-2) by the introduction of copper (Cu). The characterization and theoretical calculation results reveal that the incorporation of Cu2+ ion into the OMS-2 structure led to a rise in specific surface area and pore volume, weakening of Mn-O bonds, higher proportion of the low-coordinated oxygen species adsorbed in oxygen vacancies (Oads) and an increase in the average oxidation state of manganese. These structural modifications were discovered to considerably reduce the apparent activation energy (Ea), thus ultimately significantly enhancing the CO oxidation activity (T99 at 148 ℃at GHSV = 13,200 h-1) than the original OMS-2 (T99 = 215 ℃ at GHSV = 13,200 h-1). Furthermore, In-situ diffuse reflectance infrared Fourier transform (DRIFT) and In-situ near-ambient pressure X-ray photoelectron spectroscopy (in situ NAP-XPS) results indicate that the bimetallic synergy enhanced by doping strategy accelerates the conversion of oxygen to chemisorbed oxygen species and the reaction rate of CO oxidation through Mn3++Cu2+↔Mn4++Cu+ redox cycle. The findings of this study offer novel perspectives on the design of catalysts with exceptional performance in CO oxidation.
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Affiliation(s)
- Chao Jin
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Wenzhe Si
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Ya Chen
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Xiaoguang Zhao
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Bin Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Yu Shen
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Qiangqiang Zhu
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Yang Chu
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Feng Liu
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China
| | - Mingfeng Li
- Sinopec Research Institute of Petroleum Processing Co., Ltd, Beijing 100083, China.
| | - Junhua Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
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Jiang X, Zhang J, Liu X, Wang Z, Guo X, Li C. Deeper Insight into the Role of Organic Ammonium Cations in Reducing Surface Defects of the Perovskite Film. Angew Chem Int Ed Engl 2022; 61:e202115663. [PMID: 34989073 DOI: 10.1002/anie.202115663] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Indexed: 12/14/2022]
Abstract
Organic ammonium salts (OASs) have been widely used to passivate perovskite defects. The passivation mechanism is usually attributed to coordination of OASs with unpaired lead or halide ions, yet ignoring their interaction with excess PbI2 on the perovskite film. Herein, we demonstrate that OASs not only passivate defects by themselves, but also redistribute excess aggregated PbI2 into a discontinuous layer, augmenting its passivation effect. Moreover, alkyl OAS is more powerful to disperse PbI2 than a F-containing one, leading to better passivation and device efficiency because F atoms restrict the intercalation of OAS into PbI2 layers. Inspired by this mechanism, exfoliated PbI2 nanosheets are adopted to provide better dispersity of PbI2 , further boosting the efficiency to 23.14 %. Our finding offers a distinctive understanding of the role of OASs in reducing perovskite defects, and a route to choosing an OAS passivator by considering substitution effects rather than by trial and error.
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Affiliation(s)
- Xiaoqing Jiang
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Jiafeng Zhang
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaotao Liu
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,School of Materials Science and Engineering & National Institute for Advanced Materials, Nankai University, Tianjin, 300350, China
| | - Ziyuan Wang
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Xin Guo
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Can Li
- State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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