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Wilson WN, Whittington J, Rai N. Solvent structure and dynamics over Brønsted acid MWW zeolite nanosheets. J Chem Phys 2024; 160:224703. [PMID: 38856066 DOI: 10.1063/5.0211705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/23/2024] [Indexed: 06/11/2024] Open
Abstract
In the liquid phase of heterogeneous catalysis, solvent plays an important role and governs the kinetics and thermodynamics of a reaction. Although it is often difficult to quantify the role of the solvent, it becomes particularly challenging when a zeolite is used as the catalyst. This difficulty arises from the complex nature of the liquid/zeolite interface and the different solvation environments around catalytically active sites. Here, we use ab initio molecular dynamics simulations to probe the local solvation structure and dynamics of methanol and water over MWW zeolite nanosheets with varying Brønsted acidity. We find that the zeolite framework and the number and location of the acid sites in the zeolite influence the structure and dynamics of the solvent. In particular, methanol is more likely to be in the vicinity of the aluminum (Al3+) at the T4 site than at T1 due to easy accessibility. The methanol oxygen binds strongly to the Al at the T4 site, weakening the Al-O for the bridging acid site, which results in the formation of the silanol group, significantly reducing the acidity of the site. The behavior of methanol is in direct contrast to that of water, where protons can easily propagate from the zeolite to the solvent molecules regardless of the acid site location. Our work provides molecular-level insights into how solvent interacts with zeolite surfaces, leading to an improved understanding of the catalytic site in the MWW zeolite nanosheet.
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Affiliation(s)
- Woodrow N Wilson
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - Justin Whittington
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - Neeraj Rai
- Dave C. Swalm School of Chemical Engineering and Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, Mississippi 39762, USA
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2
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Yang R, Xu S, Wang X, Xiao Y, Li J, Hu C. Selective Stereoretention of Carbohydrates upon C-C Cleavage Enabling D-Glyceric Acid Production with High Optical Purity over a Ag/γ-Al 2O 3 Catalyst. Angew Chem Int Ed Engl 2024; 63:e202403547. [PMID: 38485666 DOI: 10.1002/anie.202403547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Indexed: 04/06/2024]
Abstract
Chiral carboxylic acid production from renewable biomass by chemocatalysis is vitally important for reducing our carbon footprint, but remains underdeveloped. We herein establish a strategy that make use of a stereogenic center of biomass to achieve a rare example of D-glyceric acid production with the highest yield (86.8 %) reported to date as well as an excellent ee value (>99 %). Unlike traditional asymmetric catalysis, chiral catalysts/additives are not required. Ample experiments combined with quantum chemical calculations established the origins of the stereogenic center and catalyst performance. The chirality at C4 in D-xylose was proved to be retained and successfully delivered to C2 in D-glyceric acid during C-C cleavage. The remarkable cooperative-roles of Ag+ and Ag0 in the constructed Ag/γ-Al2O3 catalyst are disclosed as the crucial contributors. Ag+ was responsible for low-temperature activation of D-xylose, while Ag0 facilitated the generation of active O* from O2. Ag+ and active O* cooperatively promoted the precise cleavage of the C2-C3 bond, and more importantly O* allowed the immediate fast oxidization of the D-glyceraldehyde intermediate to stabilize D-glyceric acid, thereby inhibiting the side reaction that induced racemization. This strategy makes a significant breakthrough in overcoming the limitation of poor enantioselectivity in current chemocatalytic conversion of biomass.
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Affiliation(s)
- Ruofeng Yang
- Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, No. 29 Wangjiang Road, Chengdu, Sichuan, 610064, PR China
| | - Shuguang Xu
- College of Chemical Engineering, Sichuan University No.24 South Section 1, Yihuan Road, Chengdu, Sichuan, 610065, PR China
| | - Xiaoyan Wang
- Analysis and Test Center, Sichuan University, No. 29 Wangjiang Road, Chengdu, Sichuan, 610064, PR China
| | - Yuan Xiao
- Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, No. 29 Wangjiang Road, Chengdu, Sichuan, 610064, PR China
| | - Jianmei Li
- Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, No. 29 Wangjiang Road, Chengdu, Sichuan, 610064, PR China
| | - Changwei Hu
- Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, No. 29 Wangjiang Road, Chengdu, Sichuan, 610064, PR China
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3
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Wang Q, Li T, Zhu C, Huang X, Yang G. Molecular insights for uranium(VI) adsorption at nano-TiO2 surfaces and reduction by alcohols and biomass sugars. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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4
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Qu H, Zhou S, Su Y, Yang X, Zhou L. Cost-effective and fast synthesis of Sn-β zeolite with less silanol defects for efficient conversion of glucose to methyl lactate. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Zhang Z, Berdugo-Díaz CE, Bregante DT, Zhang H, Flaherty DW. Aldol Condensation and Esterification over Ti-Substituted *BEA Zeolite: Mechanisms and Effects of Pore Hydrophobicity. ACS Catal 2022. [DOI: 10.1021/acscatal.1c04518] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhongyao Zhang
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Urbana, Illinois 61801, United States
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Claudia E. Berdugo-Díaz
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Daniel T. Bregante
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Hongbo Zhang
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - David W. Flaherty
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, Urbana, Illinois 61801, United States
- Department of Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
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6
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Zhu C, Wang Q, Huang X, Li T, Yang G. Microscopic understanding about adsorption and transport of different Cr(VI) species at mineral interfaces. JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125485. [PMID: 33677319 DOI: 10.1016/j.jhazmat.2021.125485] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/10/2021] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Cr(VI) ranks as one of the most toxic heavy metals and herein, microscopic mechanisms for adsorption and transport of different Cr(VI) oxyanions (Cr2O72- and CrO42-) at kaolinite interfaces are addressed by dispersion-corrected periodic density functional theory calculations. Cr(VI) oxyanions adsorb favorably at both tetrahedral and octahedral surfaces, and K+ ions serve as bridge for Cr(VI) oxyanions and tetrahedral surfaces while Cr(VI) oxyanions serve as bridge for K+ ions and octahedral surfaces. Adsorption structures are altered significantly by pH variation, and stability trends at different pH ranges are deciphered by the dominant interaction force with clay surfaces: Electrostatic interaction with K+ ions at tetrahedral surfaces whereas combined action of electrostatic and H-bonding interactions with Cr(VI) oxyanions at octahedral surfaces. Electron transfers are strongly pH-dependent, and clay surfaces serve as electron reservoirs. CrO42- rather than Cr2O72- is dominant at clay interfaces, and HCrO4- can co-exist under acidic conditions. Cr2O72- transformation to CrO42- is kinetically blocked at pH ≈ PZC while preferred at pH < PZC. Cr(VI) removal and reclamation should proceed at pH > 7.0 and pH < PZC, respectively. Results greatly promote the understanding about Cr(VI) bioavailability and fate in surficial environments and are also useful for Cr(VI) removal and reclamation.
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Affiliation(s)
- Chang Zhu
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Qian Wang
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Xiaoxiao Huang
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Tingting Li
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China.
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7
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Zhu C, Huang X, Li T, Wang Q, Yang G. Mechanisms for Cr(VI) reduction by alcohols over clay edges: Reactive differences between ethanol and ethanediol, and selective conversions to Cr(IV), Cr(III) and Cr(II) species. J Colloid Interface Sci 2021; 603:37-47. [PMID: 34186408 DOI: 10.1016/j.jcis.2021.06.123] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/19/2021] [Accepted: 06/21/2021] [Indexed: 11/30/2022]
Abstract
Catalytic reduction by alcohols over clay minerals works efficiently under a wide range of pH and represents an emerging approach to control Cr(VI) contamination. Herein, mechanisms for Cr(VI) adsorption and reduction at clay edges are addressed by dispersion-corrected periodic DFT calculations, considering different active sites, and types (monohydric and polyhydric) and coverage of alcohols. Cr(VI) adsorbs favorably at clay edges, forming direct bonds and strong H-bonds. Mechanisms for Cr(VI) reduction by alcohols are largely determined by π-conjugation development, and efficient conversion conduces to Cr(VI) removal. Cr(II), Cr(III) and Cr(IV) are useful for different purposes, and high selectivity towards these products is realized through rational catalysts design: 1) Cr(IV) dominates at Al3+ site with all ethanol coverage, Al3+ site with high-coverage ethanediol, and Mg2+ site with low-coverage ethanol; 2) Cr(III) dominates at Al3+ and Mg2+ sites with low-coverage ethanediol; 3) Cr(II) dominates at Mg2+ site with high-coverage ethanol or ethanediol. Results agree finely with experimental observations available, and significant new insights have been provided for Cr management and recycling. Detailed electronic structure and vibrational analyses, which can also guide future experimental studies, manifest that Cr(VI) reduction progresses are effectively monitored by ESR and FT-IR techniques.
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Affiliation(s)
- Chang Zhu
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Xiaoxiao Huang
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Tingting Li
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Qian Wang
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environments & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China.
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8
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Yang G, Zhou L. Acid rain formation through catalytic transformation of sulfur dioxide over clay dusts: remarkable promotion by a vicinal aluminium site. Catal Sci Technol 2021. [DOI: 10.1039/d0cy02069a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mechanisms for catalytic SO2 transformation to H2SO4 over clay dusts have been unraveled at a molecular level. All O atoms in ozone (especially molecular oxygen) are effective oxidants due to remarkable promotion of a vicinal Al3+ site.
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Affiliation(s)
- Gang Yang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process Southwest University
- Chongqing 400715
- China
| | - Lijun Zhou
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process Southwest University
- Chongqing 400715
- China
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9
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Adsorption and isomerization of amino acids within zeolites: Impacts of acidity, amine functionalization, pore topology and sidechains. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.111088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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10
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Yang G, Zhou L. Montmorillonite-catalyzed conversions of carbon dioxide to formic acid: Active site, competitive mechanisms, influence factors and origin of high catalytic efficiency. J Colloid Interface Sci 2020; 563:8-16. [PMID: 31865051 DOI: 10.1016/j.jcis.2019.12.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/10/2019] [Accepted: 12/15/2019] [Indexed: 11/30/2022]
Abstract
Design of heterogeneous catalysts for CO2 conversions to value-added chemicals is highly desirable. Montmorillonite and other clay minerals have been used widely in catalytic reactions including CO2 hydrogenation, while a molecular-level understanding remains lacking. In this study, periodic density functional theory calculations are employed and a comprehensive understanding about montmorillonite-catalyzed CO2 hydrogenation to formic acid is given, including active site, mechanism, influence factors, competitive reaction paths, and origin of superior catalysis. Catechol that is readily available and can also be considered as a fragment of abundantly distributed humic substances is an effective hydrogen source. The penta-coordinated M3+ (M2+) sites of edge surfaces are active sites, and reactions occur preferentially at M2+ rather than M3+ sites. The catalytic activities depend strongly on the identity of M2+ (M3+) cations, and all reaction paths follow the concerted mechanisms transferring two hydrogen atoms in one step, with those producing formate being highly preferred. M2+/Al3+ substitutions and substituent effects are two critical factors to affect catalytic activities, and with synergy of Mg2+/Al3+ substitutions and -NMe2 substituent, reactions are exergonic (-0.09 eV) and activation barriers are so low (0.48 eV) that formate can be facilely produced at ambient conditions. Edge surfaces of clay minerals are bifunctional catalysts, with M2+ cations showing Lewis acids and MOH groups playing similar effects as basic additives. Results provide new insights about heterogeneous catalysis of CO2 hydrogenation and other reactions.
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Affiliation(s)
- Gang Yang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China; State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
| | - Lijun Zhou
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
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11
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Charge reversal and anion effects during adsorption of metal ions at clay surfaces: Mechanistic aspects and influence factors. Chem Phys 2020. [DOI: 10.1016/j.chemphys.2019.110575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Yang X, Lv B, Lu T, Su Y, Zhou L. Promotion effect of Mg on a post-synthesized Sn-Beta zeolite for the conversion of glucose to methyl lactate. Catal Sci Technol 2020. [DOI: 10.1039/c9cy02376c] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mg-Sn-Beta zeolites with different Mg/Sn molar ratios were prepared from the parent deAl-Beta by a coimpregnation method. It shows higher selectivity for the conversion of glucose to methyl lactate than post-synthesized Sn-Beta.
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Affiliation(s)
- Xiaomei Yang
- Green Catalysis Center and College of Chemistry
- Zhengzhou University
- Zhengzhou 450001
- China
| | - Bin Lv
- Green Catalysis Center and College of Chemistry
- Zhengzhou University
- Zhengzhou 450001
- China
| | - Tianliang Lu
- School of Chemical Engineering
- Zhengzhou University
- Zhengzhou 450001
- China
| | - Yunlai Su
- Green Catalysis Center and College of Chemistry
- Zhengzhou University
- Zhengzhou 450001
- China
| | - Lipeng Zhou
- Green Catalysis Center and College of Chemistry
- Zhengzhou University
- Zhengzhou 450001
- China
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13
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Zhang Y, Chen H, Gao Y, Yao Z, Wang J, Zhang B, Luo K, Du S, Su DS, Zhang J. MoO x Nanoparticle Catalysts for d-Glucose Epimerization and Their Electrical Immobilization in a Continuous Flow Reactor. ACS APPLIED MATERIALS & INTERFACES 2019; 11:44118-44123. [PMID: 31682102 DOI: 10.1021/acsami.9b13848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Activity and immobilization of catalysts in liquid-phase reactions seem not to coexist. We report here the excellent activity of an MoOx nanoparticle (NP) catalyst for d-glucose epimerization to d-mannose and the electrical immobilization of NPs in a flow reaction. Prior to that, a green and one-pot method to synthesize the MoOx NPs (3.05 nm) via oxidizing metal Mo by hydrogen peroxide was presented. The NPs overwhelmed the reported catalysts including epimerase for d-glucose epimerization, originating from a strong interaction between the NPs and the reactant that was demonstrated by ex situ and in situ characterizations and theoretical calculations. The electrically charged feature of NPs inspired us to find a convenient way to "immobilize" them inside an activated carbon bed, and thereby, a flow reactor was assembled. The continuous epimerization was run under 24 V for 16 days with an almost unchanged activity, and only 3.2% of total Mo was lost.
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Affiliation(s)
- Yexin Zhang
- Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Ningbo Institute of Materials Technology & Engineering , Chinese Academy of Sciences , 1219 Zhongguan West Road , Ningbo 315201 , Zhejiang , People's Republic of China
- University of the Chinese Academy of Sciences , 19A Yuquan Road , Beijing 100049 , Beijing , People's Republic of China
| | - Hui Chen
- Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Ningbo Institute of Materials Technology & Engineering , Chinese Academy of Sciences , 1219 Zhongguan West Road , Ningbo 315201 , Zhejiang , People's Republic of China
- University of the Chinese Academy of Sciences , 19A Yuquan Road , Beijing 100049 , Beijing , People's Republic of China
| | - Yijing Gao
- Institute of Industrial Catalysis, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering , Zhejiang University of Technology , 18 Chaowang Road , Hangzhou 310032 , Zhejiang , People's Republic of China
| | - Zihao Yao
- Institute of Industrial Catalysis, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering , Zhejiang University of Technology , 18 Chaowang Road , Hangzhou 310032 , Zhejiang , People's Republic of China
| | - Jianguo Wang
- Institute of Industrial Catalysis, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, College of Chemical Engineering , Zhejiang University of Technology , 18 Chaowang Road , Hangzhou 310032 , Zhejiang , People's Republic of China
| | - Bingsen Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , 72 Wenhua Road , Shenyang 110016 , Liaoning , People's Republic of China
- University of the Chinese Academy of Sciences , 19A Yuquan Road , Beijing 100049 , Beijing , People's Republic of China
| | - Kan Luo
- Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Ningbo Institute of Materials Technology & Engineering , Chinese Academy of Sciences , 1219 Zhongguan West Road , Ningbo 315201 , Zhejiang , People's Republic of China
| | - Shiyu Du
- Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Ningbo Institute of Materials Technology & Engineering , Chinese Academy of Sciences , 1219 Zhongguan West Road , Ningbo 315201 , Zhejiang , People's Republic of China
- University of the Chinese Academy of Sciences , 19A Yuquan Road , Beijing 100049 , Beijing , People's Republic of China
| | - Dang Sheng Su
- Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Road , Dalian 116023 , Liaoning , People's Republic of China
- University of the Chinese Academy of Sciences , 19A Yuquan Road , Beijing 100049 , Beijing , People's Republic of China
| | - Jian Zhang
- Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Ningbo Institute of Materials Technology & Engineering , Chinese Academy of Sciences , 1219 Zhongguan West Road , Ningbo 315201 , Zhejiang , People's Republic of China
- University of the Chinese Academy of Sciences , 19A Yuquan Road , Beijing 100049 , Beijing , People's Republic of China
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14
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Wang Q, Zhu C, Huang X, Yang G. Abiotic reduction of uranium(VI) with humic acid at mineral surfaces: Competing mechanisms, ligand and substituent effects, and electronic structure and vibrational properties. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 254:113110. [PMID: 31479808 DOI: 10.1016/j.envpol.2019.113110] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 07/30/2019] [Accepted: 08/23/2019] [Indexed: 06/10/2023]
Abstract
Abiotic reduction represents an attractive technology to control U(VI) contamination. In this work, an abiotic route of U(VI) reduction with humic acid at mineral surfaces is proposed and reaction mechanisms are addressed by periodic density functional theory calculations. Different influencing factors such as ligand effect, content of CO32- ligands and substituent effect are inspected. The coordination chemistry of uranyl(VI) surface complexes relies strongly on substrates and ligands, and the calculated results are in good agreements with experimental observations available. For the OH- ligand, two competitive mechanisms co-exist that respectively produce the U(IV) and U(V) species, and the former is significantly preferred because of lower energy barriers. Instead, the NO3- ligand leads to the formation of U(V) while for the Cl- ligand, the U(VI) surface complex remains very stable and is not likely to be reduced because of very high energy barriers. The U(V) and U(IV) complexes are the predominant products for low and high CO32- contents, respectively. Accordingly, the abiotic reduction processes with humic acid are efficient to manage U(VI) contamination and become preferred under basic conditions or at higher CO32- contents. The U(VI) reduction is further promoted by introduction of electron-donating rather than electron-withdrawing substituents to humic acid. Electronic structure analyses and vibrational frequency assignments are calculated for the various uranium surface complexes of the reduction processes, serving as a guide for future experimental and engineered studies. The molecular-level understanding given in this work offers an abiotic route for efficient reduction of U(VI) and remediation of U(VI)-contaminated sites at ambient conditions.
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Affiliation(s)
- Qian Wang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Chang Zhu
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Xiaoxiao Huang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China.
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15
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Yun J, Zhu C, Wang Q, Hu Q, Yang G. Catalytic conversions of atmospheric sulfur dioxide and formation of acid rain over mineral dusts: Molecular oxygen as the oxygen source. CHEMOSPHERE 2019; 217:18-25. [PMID: 30396046 DOI: 10.1016/j.chemosphere.2018.10.201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 10/26/2018] [Accepted: 10/29/2018] [Indexed: 06/08/2023]
Abstract
Sulfur dioxide (SO2) ranks as a major air pollutant and is likely to generate acid rain. When molecular oxygen is the oxygen source, the regular surfaces of gibbsite (one of the most abundant mineral dusts) show no reactivity for SO2 conversions to H2SO4, while the partially dehydrated (100) surface with coordination-unsaturated Al sites becomes catalytically effective. Because of the easy availability of molecular oxygen, results manifest that acid rain can form under all atmospheric conditions and may account for the high conversion ratio of atmospheric SO2. The (100) and (001) surfaces show divergent catalytic effects, and hydrolysis is always the rate-limiting step. Path A (hydrolysis and then oxidation) is preferred for (100) surface, whereas a third path with obviously lower activation barriers is presented for (001) surface, which is non-existent for (100) surface. Atomic oxygen originating from the dissociation of molecular oxygen is catalytically active for (100) surface, while the active site of (001) surface fails to be recovered, suggesting that SO2 conversions over gibbsite surfaces are facet-controlled. This work also offers an environmentally friendly route for production of H2SO4 (one of the essential compounds in chemical industry), directly using molecular oxygen as the oxygen source.
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Affiliation(s)
- Jiena Yun
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Chang Zhu
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Qian Wang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Qiaoli Hu
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China.
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16
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Li G, Pidko EA. The Nature and Catalytic Function of Cation Sites in Zeolites: a Computational Perspective. ChemCatChem 2018. [DOI: 10.1002/cctc.201801493] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Guanna Li
- Department Chemical EngineeringDelft University of Technology Van der Maasweg 9 Delft 2629 HZ The Netherlands
| | - Evgeny A. Pidko
- Department Chemical EngineeringDelft University of Technology Van der Maasweg 9 Delft 2629 HZ The Netherlands
- ITMO University Lomonosova str. 9 St. Petersburg 191002 Russia
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