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Jin Y, Cheng H, Wang Q, Liu X, Mo S, Zhou B, Peng Y, Wang Y, Si W, Li J. Insights into in situ surface reconstruction in cobalt perovskite oxides for enhanced catalytic activity. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135113. [PMID: 38996683 DOI: 10.1016/j.jhazmat.2024.135113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/24/2024] [Accepted: 07/04/2024] [Indexed: 07/14/2024]
Abstract
An depth understanding of the fundamental interactions between surface termination and catalytic activity is crucial to prompt the properties of functional perovskite materials. The elastic energy due to size mismatch and electrostatic attraction of the charged Sr dopant by positively charged oxygen vacancies induced inert A-site surface enrichment rearrangement for perovskites. Lower temperatures could reduce A-site enrichment, but it is difficult to form perovskite crystals. La0.8Sr0.2CoO3-δ (LSCO) as a model perovskite oxide was modified with additive urea to reduce the crystallization temperature, and suppress Sr segregation. The LSCO catalysts with 600 °C annealing temperature (LSCO-600) exhibited a 19.4-fold reaction reactivity of toluene oxidation than that with 800 °C annealing temperature (LSCO-800). Combined surface-sensitive and depth-resolved techniques for surface and sub-surface analysis, surface Sr enrichment was effectively suppressed due to decreased oxygen vacancy concentration and smaller electrostatic driving force. DFT calculations and in-situ DRIFTs spectra well revealed that tuning the surface composition/termination affected the intrinsic reactivity. The catalyst surface with lower Sr enrichment could easily adsorb toluene, cleave, and decompose benzene rings, thus contributing to toluene degradation to CO2. This work demonstrates a green and efficient way to control surface composition and termination at the atomic scale for higher catalytic activity.
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Affiliation(s)
- Yanyu Jin
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; School of Chemical & Environmental Engineering, China University of Mining and Technology, Beijing 100084, China
| | - Hongjun Cheng
- School of Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Qibao Wang
- School of Chemical & Environmental Engineering, China University of Mining and Technology, Beijing 100084, China
| | - Xiaoqing Liu
- School of Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Shengpeng Mo
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Bin Zhou
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Yue Peng
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Yu Wang
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
| | - Wenzhe Si
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, 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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Pawlak J, Przybylski M, Mitura Z. An Analysis of Kikuchi Lines Observed with a RHEED Apparatus for a TiO 2-Terminated SrTiO 3 (001) Crystal. MATERIALS 2021; 14:ma14227077. [PMID: 34832477 PMCID: PMC8624205 DOI: 10.3390/ma14227077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/05/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022]
Abstract
In this study, electron diffraction patterns observed under high vacuum conditions for an SrTiO3 surface were interpreted in detail while paying special attention to the features of inelastic effects. The surface of the SrTiO2 was carefully prepared to enforce its termination with single domains of TiO2 layers at the top. The inelastic patterns were interpreted using analytical models. Two types of Kikuchi lines are recognized in this paper: those which can be described with the Bragg law and those which appear due to surface wave resonance effects. However, we also discuss that there exists a formal connection between the two types of the Kikuchi lines observed.
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Affiliation(s)
- Jakub Pawlak
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland; (J.P.); (M.P.)
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
| | - Marek Przybylski
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland; (J.P.); (M.P.)
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
| | - Zbigniew Mitura
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
- Correspondence:
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