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Cui Y, Chen Y, Cao Z, Xu L, He J, Zhu Z, Lian L, Luo X, Yang Z, Chen M. Oxidation of Toluene over the Pt-Embedded Mesoporous CeO 2 Hollow Nanospheres with Advanced Catalytic Performances. Inorg Chem 2024. [PMID: 39377731 DOI: 10.1021/acs.inorgchem.4c03562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
In this study, the novel Pt-embedded mesoporous CeO2 hollow nanospheres (Pt-MS-CeO2-H) with varying Pt contents (0.5-3.0 wt %) were facilely prepared. The Pt nanoparticles were one-pot embedded within the mesoporous shell of Pt-MS-CeO2-H and assisted with the reduction Ostwald ripening process. The traditional preparation methods often face challenges, such as the uneven distribution or aggregation of nanoparticles, as well as difficulty in maintaining high catalytic activity at low Pt content. Compared with the traditional supported Pt/MS-CeO2 catalyst, the embedding strategy facilitated precise control over the position, distribution, and uniformity of Pt nanoparticles within the CeO2 mesoporous shell. Additionally, the encapsulation process of Pt nanoparticles played a pivotal role in generating oxygen vacancies and activating surface chemical adsorption of oxygen. Resultantly, the toluene oxidation performances of 1Pt-MS-CeO2-H catalyst showed much lower T90 (171 °C) than 1Pt/MS-CeO2 (311 °C). To elucidate the underlying reasons, in situ diffuse reflectance infrared Fourier transform spectroscopy of toluene oxidation was employed to identify the reaction intermediates and pathways over these catalysts. In summary, the Pt-embedded mesoporous CeO2 hollow nanosphere catalysts were considered as potential candidates when designing high-performance toluene catalytic oxidation catalysts.
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Affiliation(s)
- Yan Cui
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
- Jiangsu Environmental Engineering Technology Co., Ltd., Nanjing 210004, China
| | - Yusheng Chen
- Academy of Environmental Planning and Design, Co. Ltd. Nanjing University, Nanjing 210024, China
| | - Zhen Cao
- College of Chemical Engineering and Environmental Chemistry, Weifang University, Weifang 261061, China
| | - Leilei Xu
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
| | - Jing He
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
| | - Zehui Zhu
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
| | - Linshui Lian
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
| | - Xue Luo
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
| | - Zhenya Yang
- Jiangsu Environmental Engineering Technology Co., Ltd., Nanjing 210004, China
| | - Mindong Chen
- Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, 210044 Nanjing, China
- School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei 230009, China
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Luo D, Liu X, Chang T, Bai J, Guo W, Zheng W, Wen X. Towards understanding the lower CH 4 selectivity of HCP-Co than FCC-Co in Fischer-Tropsch synthesis. Phys Chem Chem Phys 2024; 26:5704-5712. [PMID: 38289691 DOI: 10.1039/d3cp06041a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
In Fischer-Tropsch synthesis (FTS), the cobalt catalyst has higher C5+ and lower CH4 selectivity in the hcp phase than in the fcc phase. However, a detailed explanation of the intrinsic mechanism is still missing. The underlying reason was explored combining density functional theory, Wulff construction, and a particle-level descriptor based on the slab model of surfaces that are prevalent in the Wulff shape to provide single-particle level understanding. Using a particle-level indicator of the reaction rates, we have shown that it is more difficult to form CH4 on hcp-Co than on fcc-Co, due to the larger effective barrier difference of CH4 formation and C-C coupling on hcp-Co particles, which leads to the lower CH4 selectivity of hcp-Co in FTS. Among the exposed facets of fcc-Co, the (311) surface plays a pivotal role in promoting CH4 formation. The reduction of CH4 selectivity in cobalt-based FTS is achievable through phase engineering of Co from fcc to hcp or by tuning the temperature and size of the particles.
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Affiliation(s)
- Dan Luo
- Shanxi Key Laboratory of Ecological Protection and Resources Utilization of Yuncheng Salt Lake, Department of Applied Chemistry, Yuncheng University, 1155 Fudan West Street, Yuncheng 044000, China
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China.
| | - Xingchen Liu
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, P. R. China
| | - Tong Chang
- Shanxi Key Laboratory of Ecological Protection and Resources Utilization of Yuncheng Salt Lake, Department of Applied Chemistry, Yuncheng University, 1155 Fudan West Street, Yuncheng 044000, China
| | - Jiawei Bai
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China.
| | - Wenping Guo
- National Energy Center for Coal to Liquids, Synfuels China Co., Ltd, Huairou District, Beijing, 101400, China
| | - Wentao Zheng
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China.
| | - Xiaodong Wen
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing, 100049, P. R. China
- National Energy Center for Coal to Liquids, Synfuels China Co., Ltd, Huairou District, Beijing, 101400, China
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Wang F, Luo M, Liu Q, Shao C, Yang Z, Liu X, Guo J. Preparation of Pt/MgAl2O4 Decalin Dehydrogenation Catalyst for Chemical Hydrogen Storage Application. Catal Letters 2023. [DOI: 10.1007/s10562-023-04283-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production. ENERGIES 2021. [DOI: 10.3390/en14113347] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.
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Wang Y, Li HX, Li XG, Xiao WD, Chen D. Hydrogenation of CO to olefins over a supported iron catalyst on MgAl 2O 4 spinel: effects of the spinel synthesis method. RSC Adv 2020; 10:40815-40829. [PMID: 35519224 PMCID: PMC9057707 DOI: 10.1039/d0ra08387a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 10/20/2020] [Indexed: 11/24/2022] Open
Abstract
In the process of CO hydrogenation to olefins by the Fischer–Tropsch synthesis (FTO), the support is a key factor in the activity, selectivity, and thermal and chemical stability of the catalysts, and magnesium aluminate spinel (MgAl2O4) has recently been reported to be very effective. In this work, three methods, namely, citric acid solution combustion (MAC), EDTA sol–gel (MAG) and NH3-coprecipitation (MAP) have been employed to prepare the spinel with detailed characterization of the structure, specific surface area, porosity, and alkalinity properties of both the as-synthesized spinel and the supported catalysts. The results showed that MAC and MAG possessed stronger basicity with more homogeneous particle sizes and narrower distribution of the pore size due to the formation of the metal-nitrate–chelate-complex. This led to a large quantity of gas being released during calcination, however, stronger interactions between the active phase and MAC resulted in lower CO conversion. The catalyst supported on MAP (CMAP) exhibited the highest CO conversion, the highest selectivity of lower olefins, the shortest induction period of reaction, and the lowest AFS chain growth probability; thus, MAP was suggested as an applicable synthetic method. Based on the CMAP catalyst, the effects of the operational conditions were investigated and a 200 hour stability test was carried out with satisfactory performance. In the process of CO hydrogenation to olefins by the Fischer–Tropsch synthesis, the support is a key factor in the activity, selectivity, and thermal and chemical stability of the catalysts, and magnesium aluminate spinel has recently been reported to be very effective.![]()
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Affiliation(s)
- Yu Wang
- Shanghai Jiao Tong University Shanghai China
| | - Hou-Xing Li
- Shanghai Jiao Tong University Shanghai China
| | - Xue-Gang Li
- Shanghai Jiao Tong University Shanghai China
| | - Wen-De Xiao
- Shanghai Jiao Tong University Shanghai China
| | - De Chen
- Norwegian University of Science and Technology 7491 Trondheim Norway
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