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Dry etching of ternary metal carbide TiAlC via surface modification using floating wire-assisted vapor plasma. Sci Rep 2022; 12:20394. [DOI: 10.1038/s41598-022-24949-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
AbstractDry etching of ternary metal carbides TiAlC has been first developed by transferring from wet etching to dry etching using a floating wire (FW)-assisted Ar/ammonium hydroxide vapor plasma. FW-assisted non-halogen vapor plasma generated at medium pressure can produce high-density reactive radicals (NH, H, and OH) for TiAlC surface modifications such as hydrogenation and methylamination. A proposed mechanism for dry etching of TiAlC is considered with the formation of the volatile products from the modified layer.
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Wang J, Shen X, Zhang Y, Lu J, Liu M, Ling L, Liao J, Chang L, Xie K. Synthesis of the Hierarchical TS-1 Using TritonX Homologues for Hydroxylation of Benzene. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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3
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Insights into the role of titanium sites in cyclohexanone ammoximation over titanium silicalite-1. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112298] [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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4
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Li F, Zhou Z, Qin J, Liu C, Liu Y, He B, Xia G, Wu W. Evaporation‐Induced Self‐Assembly Method Route to TiO
2
−SiO
2
Catalysts with Hierarchical Pores and Their Oximation of Ketones and Aldehydes. ChemistrySelect 2021. [DOI: 10.1002/slct.202100487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Fanqing Li
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
| | - Zhiwei Zhou
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
| | - Juan Qin
- Productivity Center of Jiangsu Province Technology and Finance Service Center of Jiangsu Province Nanjing 210042 P. R. China
| | - Chuanfa Liu
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
| | - Yangyang Liu
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
| | - Binbin He
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
| | - Guangbo Xia
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
| | - Wenliang Wu
- College of Chemical Engineering Nanjing Tech University Nanjing 210009 P. R. China
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A DFT study on catalytic oxidative desulfurization with H 2O 2 over Ti-MWW zeolite. J Mol Model 2019; 25:106. [PMID: 30929089 DOI: 10.1007/s00894-019-3989-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 03/13/2019] [Indexed: 10/27/2022]
Abstract
The catalytic mechanism of Ti-MWW in oxidative desulfurization with H2O2 was investigated by quantum chemical calculations. A defect model (Ti-d) and a perfect model (Ti-p) were proposed for Ti-MWW, and two possible reaction pathways starting from Ti-d and Ti-p were considered. On Ti-d, the hydroperoxy bidentate intermediate TiOOH (η2) was formed by activating H2O2 at the Ti center. Afterwards, aromatic sulfides were oxidized to sulfoxides and to ultimate sulfones by TiOOH (η2). The order of oxidation reactivity was benzothiophene > dibenzothiophene > thiophene, conforming to experimental observations. The Ti-p pathway proposed for oxidation of sulfides with H2O2 resulted in higher energy barriers compared to the Ti-d pathway. Natural bond orbital charge analysis was carried out to understand the charge distribution. This work showed that the defective Ti-MWW model for oxidative desulfurization was more active than the perfect model. Graphical abstract Catalytic oxidative desulfurizationwith H2O2 over Ti-MWW zeolite.
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Jin H, Meng C, He G, Guo X, Yang S. Green synthesis of acetaldehyde oxime using ammonia oxidation in the TS-1/H2O2 system. REACTION KINETICS MECHANISMS AND CATALYSIS 2018. [DOI: 10.1007/s11144-018-1440-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Wang H, Deng Y, Zhou R. Aromatic sulfur compounds oxidation with H2O2 over fully coordinated and defect sites in Ti-beta zeolites: evaluation by density functional theory. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2241-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Thiophene oxidation with H2O2 over defect and perfect titanium silicalite-1: a computational study. REACTION KINETICS MECHANISMS AND CATALYSIS 2018. [DOI: 10.1007/s11144-018-1350-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Li M, Yan X, Zhu M, Wang M, Zhou D. Insight into the stereoselectivity of TS-1 in epoxidation of cis/ trans-2-hexene: a computational study. Catal Sci Technol 2018. [DOI: 10.1039/c8cy01631c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mechanism of the stereoselectivity forcis/trans-2-hexene epoxidation in TS-1 zeolite was studied using density functional theory and the ONIOM scheme.
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Affiliation(s)
- Mengzhao Li
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Xiaoyue Yan
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Meiyu Zhu
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Meiqi Wang
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Danhong Zhou
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
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Qin J, Lin C, Cheruiyot P, Mkpanam S, Good-Mary Duma N. Potential effects of rainwater-borne hydrogen peroxide on pollutants in stagnant water environments. CHEMOSPHERE 2017; 174:90-97. [PMID: 28160681 DOI: 10.1016/j.chemosphere.2017.01.111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 01/13/2017] [Accepted: 01/22/2017] [Indexed: 06/06/2023]
Abstract
Microcosm experiments were conducted to examine the effects of rainwater-borne H2O2 on inactivation of water-borne coliforms, oxidation of ammonia and nitrite, and degradation of organic pollutants in canal and urban lake water. The results show that the soluble iron in the investigated water samples was sufficiently effective for reaction with H2O2 in the simulated rainwater-affected stagnant water to produce OH (Fenton reaction), which inactivated coliform bacteria even at a H2O2 dose as low as 5 μM within just 1 min of contact time. Coliform inhibition could last for at least 1 h and repeated input of H2O2 at a 30 min interval allowed maintenance of microbial inhibition for at least 3 h. Nitrification was also impeded by the Fenton process. The resulting inhibition of ammonia-oxidizing microbes reduced the removal rate of NH4+ and the emission of gaseous N species. In the presence of H2O2 at a dose of 20 μM, Fenton-driven chemical oxidation appeared to outplay the impediment of biodegradation caused by inhibited microbial activities in terms of removing total polycyclic aromatic hydrocarbons from the water column. The findings point to a potential research direction that may help to explain the dynamics of water-borne pollutants in ambient water environments.
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Affiliation(s)
- Junhao Qin
- College of Resources and Environment, South China Agricultural University, Guangzhou, China; School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom
| | - Chuxia Lin
- School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom.
| | - Patrick Cheruiyot
- School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom
| | - Sandra Mkpanam
- School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom
| | - Nelisiwe Good-Mary Duma
- School of Environment and Life Science, University of Salford, Greater Manchester, M5 4WT, United Kingdom
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Majumdar D, Baugh N, Bhattacharya SK. Ultrasound assisted formation of reduced graphene oxide-copper (II) oxide nanocomposite for energy storage applications. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2016.10.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Li M, Wang Y, Wu Y, Wang M, Zhou D. Structure and catalytic activity of a newly proposed titanium species in a Ti-YNU-1 zeolite: a density functional theory study. Catal Sci Technol 2017. [DOI: 10.1039/c7cy01470h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory was applied to investigate the structure of the framework titanium (Ti) species in the Ti-YNU-1 zeolite, and to evaluate its catalytic activity for 1-hexene epoxidation with H2O2 as the oxidant.
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Affiliation(s)
- Mengzhao Li
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Yichen Wang
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Yue Wu
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Meiqi Wang
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
| | - Danhong Zhou
- College of Chemistry and Chemical Engineering
- Liaoning Normal University
- Dalian 116029
- People's Republic of China
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The Reaction Mechanism of Acetaldehyde Ammoximation to Its Oxime in the TS-1/H2O2 System. Catalysts 2016. [DOI: 10.3390/catal6070109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Dong C, Wang K, Zhang J, Luo G. Reaction kinetics of cyclohexanone ammoximation over TS-1 catalyst in a microreactor. Chem Eng Sci 2015. [DOI: 10.1016/j.ces.2015.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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15
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Li H, Zhou D, Tian D, Shi C, Müller U, Feyen M, Yilmaz B, Gies H, Xiao FS, De Vos D, Yokoi T, Tatsumi T, Bao X, Zhang W. Framework Stability and Brønsted Acidity of Isomorphously Substituted Interlayer-Expanded Zeolite COE-4: A Density Functional Theory Study. Chemphyschem 2014; 15:1700-7. [DOI: 10.1002/cphc.201301033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 02/04/2014] [Indexed: 11/05/2022]
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Sangthong W, Probst M, Limtrakul J. Conversion of CO2 and C2H6 to propanoic acid over a Au-exchanged MCM-22 zeolite. Chemphyschem 2014; 15:514-20. [PMID: 24375933 DOI: 10.1002/cphc.201300931] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/25/2013] [Indexed: 11/09/2022]
Abstract
Finding novel catalysts for the direct conversion of CO2 to fuels and chemicals is a primary goal in energy and environmental research. In this work, density functional theory (DFT) is used to study possible reaction mechanisms for the conversion of CO2 and C2H6 to propanoic acid over a gold-exchanged MCM-22 zeolite catalyst. The reaction begins with the activation of ethane to produce a gold ethyl hydride intermediate. Hydrogen transfers to the framework oxygen leads then to gold ethyl adsorbed on the Brønsted-acid site. The energy barriers for these steps of ethane activation are 9.3 and 16.3 kcal mol(-1), respectively. Two mechanisms of propanoic acid formation are investigated. In the first one, the insertion of CO2 into the Au-H bond of the first intermediate yields gold carboxyl ethyl as subsequent intermediate. This is then converted to propanoic acid by forming the relevant C-C bond. The activation energy of the rate-determining step of this pathway is 48.2 kcal mol(-1). In the second mechanism, CO2 interacts with gold ethyl adsorbed on the Brønsted-acid site. Propanoic acid is formed via protonation of CO2 by the Brønsted acid and the simultaneous formation of a bond between CO2 and the ethyl group. The activation energy there is 44.2 kcal mol(-1), favoring this second pathway at least at low temperatures. Gold-exchanged MCM-22 zeolite can therefore, at least in principle, be used as the catalyst for producing propanoic acid from CO2 and ethane.
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Affiliation(s)
- Winyoo Sangthong
- Laboratory for Computational and Applied Chemistry, Department of Chemistry, Faculty of Science and Center of Nanotechnology, Kasetsart University Research and Development Institute, Kasetsart University, Bangkok 10900 (Thailand), Fax: (+66) 2-562-5555; NANOTEC Center for Nanoscale Materials for Green Nanotechnology, Kasetsart University, Bangkok 10900 (Thailand); Center for Advanced Studies in Nanotechnology and its Applications in Chemical, Food, and Agricultural Industries, Kasetsart University, Bangkok 10900 (Thailand)
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