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Yan X, Zhao L, Huang Y, Zhang J, Jiang S. Three-dimensional porous CuO-modified CeO 2-Al 2O 3 catalysts with chlorine resistance for simultaneous catalytic oxidation of chlorobenzene and mercury: Cu-Ce interaction and structure. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131585. [PMID: 37163894 DOI: 10.1016/j.jhazmat.2023.131585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 05/12/2023]
Abstract
Chlorine poisoning effects are still challenging to develop efficient catalysts for applications in chlorobenzene (CB) and mercury (Hg0) oxidation. Herein, three-dimensional porous CuO-modified CeO2-Al2O3 catalysts with macroporous framework and mesoporous walls prepared via a dual template method were employed to study simultaneous oxidation of CB and Hg0. CuO-modified CeO2-Al2O3 catalysts with three-dimensional porous structure exhibited outstanding activity and stability for simultaneous catalytic oxidation of CB and Hg0. The results demonstrated that the addition of CuO into CeO2-Al2O3 can simultaneously enhance the acid sites and redox properties through the electronic inductive effect between CuO and CeO2 (Cu2++Ce3+↔Cu++Ce4+). Importantly, the synergistic effect between Cu and Ce species can induce abundant oxygen vacancies formation, produce more reactive oxygen species and facilitate oxygen migration, which is beneficial for the deep oxidation of chlorinated intermediates. Moreover, macroporous framework and mesoporous nanostructure dramatically improved the specific surface area for enhancing the contact efficiency between reactants and active sites, leading to a remarkable decrease of byproducts deposition. CB and Hg0 had function of mutual promotion in this reaction system. In tune with the experimental results, the possible mechanistic pathways for simultaneous catalytic oxidation of CB and Hg0 were proposed.
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Affiliation(s)
- Xin Yan
- College of Environmental and Resources, Xiangtan University, Xiangtan 411105, PR China; Hunan Provincial Environmental Protection of Engineering Technology Center of Air Complex Pollution Control (XTU), Xiangtan 411105, PR China
| | - Lingkui Zhao
- College of Environmental and Resources, Xiangtan University, Xiangtan 411105, PR China; Hunan Provincial Environmental Protection of Engineering Technology Center of Air Complex Pollution Control (XTU), Xiangtan 411105, PR China.
| | - Yan Huang
- College of Environmental and Resources, Xiangtan University, Xiangtan 411105, PR China; Hunan Provincial Environmental Protection of Engineering Technology Center of Air Complex Pollution Control (XTU), Xiangtan 411105, PR China
| | - Junfeng Zhang
- College of Environmental and Resources, Xiangtan University, Xiangtan 411105, PR China; Hunan Provincial Environmental Protection of Engineering Technology Center of Air Complex Pollution Control (XTU), Xiangtan 411105, PR China
| | - Su Jiang
- College of Environmental and Resources, Xiangtan University, Xiangtan 411105, PR China; Hunan Provincial Environmental Protection of Engineering Technology Center of Air Complex Pollution Control (XTU), Xiangtan 411105, PR China
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Ma Y, Lai J, Wu J, Zhang H, Yan J, Li X, Lin X. Efficient synergistic catalysis of chlorinated aromatic hydrocarbons and NO x over novel low-temperature catalysts: Nano-TiO 2 modification and interaction mechanism. CHEMOSPHERE 2023; 315:137640. [PMID: 36584823 DOI: 10.1016/j.chemosphere.2022.137640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/12/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
For efficient and synergistic elimination of chlorinated aromatic hydrocarbons (e.g., dioxins and chlorobenzenes) and NOx at low temperatures, a novel VOx-CeOx-WOx/TiO2 catalyst was systemically studied, involving the nano-TiO2 modification and the interaction mechanism between 1,2-dichlorobenzen (1,2-DCB) catalytic oxidation (DCBCO) and NH3-SCR. The VOx-CeOx-WOx/TiO2 performed excellent oxygen storage/release capacity (OSRC) and desirable 1,2-DCB conversion efficiency (95.1-97.4%) at 160-200 ℃ via M‒K and L‒H mechanism. The nano-TiO2 modification slightly impaired the 1,2-DCB oxidation to 93.6-96.2% owing to the reduced surface area and Brønsted acidity, while it distinctly enhanced NO conversion and lowered the T50 (from 162 to 112 ℃) and T90 (from 232 to 205 ℃) by improving catalyst reducibility. Based on further synergistic catalysis evaluation and in-situ DRIFT analysis, NO enhanced the 1,2-DCB conversion and complete oxidation capacity of VOx-CeOx-WOx/TiO2 by promoting active oxygen (O2-, O-, O2-) generation and improving 1,2-DCB chemosorption and subsequent oxidation. In detail, the produced HCl and H2O improved the catalyst acidity and promoted the formation of HONO and HNO3. Moreover, their generation not only facilitated the chemisorption of NH3 but also participated in the NH3-SCR via L‒H mechanism. The ensuing problem was the competitive chemisorption among 1,2-DCB, NH3, and their subsequent intermediates. As a result, NH3 had distinct advantages in competing for acid sites and active oxygen species, especially at the higher temperature, resulting in the improved NO conversion with elevated reaction temperature but the reduced 1,2-DCB conversion. The results provided essential basics for developing new catalysts to synergistically control the emission of chloroaromatic organics and NOx at low temperature.
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Affiliation(s)
- Yunfeng Ma
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jianwen Lai
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jiayao Wu
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Hao Zhang
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jianhua Yan
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaodong Li
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaoqing Lin
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
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Lu T, Su F, Zhao Q, Li J, Zhang C, Zhang R, Liu P. Catalytic oxidation of volatile organic compounds over manganese-based oxide catalysts: Performance, deactivation and future opportunities. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121436] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Kalidhasan S, Lee HY. Preparation of TiO 2-deposited silica-based catalysts for photocatalytic decomposition of chloro-pesticide to environmentally less toxic species. CHEMOSPHERE 2022; 290:133300. [PMID: 34914956 DOI: 10.1016/j.chemosphere.2021.133300] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
Herein, titanium (IV) oxide (TiO2) loaded into montmorillonite (MK10) and sand is presented as an efficient heterogeneous catalyst for the degradation of 1,4-dichlorobenzene (DCB) as a model organic pollutant in the aqueous phase. The catalyst was synthesized by incorporating titanium isopropoxide as a precursor into MK10 through a simple solvent impregnation method, followed by direct calcination. The same protocol was applied to a clean quartz matrix. The resulting catalysts were characterized in detail using a variety of techniques. The TiO2 deposited MK10 and sand exhibited photochemical removal of DCB (>99% of 100 mg L-1) from the aqueous phase; this process followed a pseudo second-order kinetic model values in the range of Qe:111-113 mg g-1 and K2: 4-5 × 10-4 g mg-1 min-1. The kinetic plots indicate that after 30 min, the intermediates start to decrease and complete degradation occurs in 180 min. The modified materials showed fast DCB degradation kinetics under photochemical reaction conditions and adsorption under dark reaction conditions. The unmodified matrix adsorbed 99.12-99.88% of the DCB under both dark and light reaction conditions. These photocatalysts are stable, reusable, and least amount of titanium leaching. The simple two step synthesis, and high photocatalytic performance (with 10 mg of the catalyst without any oxidants) of our catalysts can be promising in environmental applications to treat similar organic pollutants in wastewater. These catalysts have enhanced activity and durability for environmental catalytic pollutant degradation reactions and can provide insights beyond single metal oxide catalysts for heterogeneous catalysis at diverse operating conditions.
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Affiliation(s)
- Sethu Kalidhasan
- Department of Chemical Engineering, The Kumoh National Institute of Technology, 61, Daehak-ro, Gumi-si, Gyeongsangbuk-do, 39177, Republic of Korea; Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl Street, POB 234, Rehovot, 7610001, Israel.
| | - Hee-Young Lee
- Department of Chemical Engineering, The Kumoh National Institute of Technology, 61, Daehak-ro, Gumi-si, Gyeongsangbuk-do, 39177, Republic of Korea.
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Lin F, Wang Q, Huang X, Jin J. Investigation of chlorine-poisoning mechanism of MnO x/TiO 2 and MnO x-CeO 2/TiO 2 catalysts during o-DCBz catalytic decomposition: Experiment and first-principles calculation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 298:113454. [PMID: 34365187 DOI: 10.1016/j.jenvman.2021.113454] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 07/16/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
The catalytic activity and stability of MnOx/TiO2 and MnOx-CeO2/TiO2 catalysts for the oxidative degradation of 1,2-dichorobenzene (o-DCBz) at low temperatures (≤275 °C) were experimentally examined. The chlorine (Cl) poisoning mechanism of the catalysts was also clarified based on the catalyst characterization combined with theoretical calculations. Experimental results show that the MnOx/TiO2 catalyst is considerably deactivated during o-DCBz catalytic decomposition, mainly due to the chlorination of the catalytic active component. Ce addition and high temperature can effectively promote the resistance of MnOx/TiO2 catalyst to Cl poisoning. Density functional theory (DFT) calculations in the framework of first-principles reveal that Cl atom prefers to anchor on surface oxygen vacancy (OV) rather than on top site of Mn atom. The adsorption of Cl atom on surface OV hinders the dissociated adsorption of O2 on surface OV and interrupts the regeneration of the surface reactive oxygen species. The adsorption of Cl atom on top site of Mn atom increases the formation energy of surface OV and damages the surface Lewis acid sites which act as the important adsorption sites for o-DCBz molecules. Ce addition causes Cl atom to adsorb preferentially onto the OV around Ce atom, which weakens the interaction between Cl atom and Mn atom. Consequently, the chlorination of the MnOx species is prevented and the oxygen mobility of the catalyst is guaranteed to some extent.
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Affiliation(s)
- Feng Lin
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China; Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Qiulin Wang
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China; Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
| | - Xiaoniu Huang
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China; Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Jing Jin
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China; Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
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