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CO2 Hydrogenation to Methane over Ni-Catalysts: The Effect of Support and Vanadia Promoting. Catalysts 2021. [DOI: 10.3390/catal11040433] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods are developed to target the “closed carbon cycle”. The catalysts supported on different metal oxides were characterized by XRD, XPS, Raman, UV-Vis, temperature-programmed techniques; then, they were tested in CO2 hydrogenation at 1 bar. Moreover, the V2O5 promotion was studied for Ni/Al2O3 catalyst. The precisely designed hydrotalcite-derived catalyst and vanadia-promoted Ni-catalysts deliver exceptional conversions for the studied processes, presenting high durability and selectivity, outperforming the best-known catalysts. The equilibrium conversion was reached at temperatures around 623 K, with the primary product of reaction CH4 (>97% CH4 yield). Although the Ni loading in hydrotalcite-derived NiWP is lower by more than 40%, compared to reference NiR catalyst and available commercial samples, the activity increases for this sample, reaching almost equilibrium values (GHSV = 1.2 × 104 h–1, 1 atm, and 293 K).
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2
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Chu YJ, Chen XM, Liu CG. Computational study on epoxidation of propylene by dioxygen using the silanol-functionalized polyoxometalate-supported osmium oxide catalyst. Inorg Chem Front 2019. [DOI: 10.1039/c9qi00900k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The silanol-functionalized POM-supported single-site Os oxide catalyst has been theoretically considered for epoxidation of propylene in the presence of dioxygen based on density functional theory calculations.
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Affiliation(s)
- Yun-Jie Chu
- Department of Chemistry
- Faculty of Science
- Beihua University
- Jilin City
- P. R. China
| | - Xue-Mei Chen
- College of Chemical Engineering
- Northeast Electric Power University
- Jilin City
- P. R. China
| | - Chun-Guang Liu
- Department of Chemistry
- Faculty of Science
- Beihua University
- Jilin City
- P. R. China
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3
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Electronic structure changes introduced by nitrogen on the N-doped VOx/TiO2 system: Consequences on partial oxidation catalysis. MOLECULAR CATALYSIS 2018. [DOI: 10.1016/j.mcat.2018.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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4
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B. HB, T. VRK, Y. W. S, P. S. SP, N. L. One-step selective synthesis of 2-chlorobenzonitrile from 2-chlorotoluene via ammoxidation. NEW J CHEM 2018. [DOI: 10.1039/c7nj03728g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Isolated and polymeric vanadia formulate V2O5/Al2O3 catalysts selective for the synthesis of 2-chlorobenzonitrile from 2-chlorotoluene in a single step through ammoxidation.
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Affiliation(s)
- Hari Babu B.
- Catalysis Laboratory
- I&PC Division
- CSIR-Indian Institute of Chemical Technology
- Hyderabad 500 007
- India
| | - Venkateswara Rao K. T.
- Catalysis Laboratory
- I&PC Division
- CSIR-Indian Institute of Chemical Technology
- Hyderabad 500 007
- India
| | - Suh Y. W.
- Department of Chemical Engineering
- Hanyang University
- Seoul 133-691
- Republic of Korea
- Research Institute of Industrial Science
| | - Sai Prasad P. S.
- Catalysis Laboratory
- I&PC Division
- CSIR-Indian Institute of Chemical Technology
- Hyderabad 500 007
- India
| | - Lingaiah N.
- Catalysis Laboratory
- I&PC Division
- CSIR-Indian Institute of Chemical Technology
- Hyderabad 500 007
- India
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5
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Yun D, Herrera JE. A novel methodology for in situ redox active site titration of TiO 2 -supported vanadia during ethanol partial oxidation catalysis. J Catal 2017. [DOI: 10.1016/j.jcat.2017.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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Ji P, Gao X, Du X, Zheng C, Luo Z, Cen K. Relationship between the molecular structure of V2O5/TiO2 catalysts and the reactivity of SO2 oxidation. Catal Sci Technol 2016. [DOI: 10.1039/c5cy00867k] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The VO site was demonstrated to play a critical role in the SO2 oxidation over V2O5/TiO2 catalysts.
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Affiliation(s)
- Peidong Ji
- State Key Laboratory of Clean Energy Utilization
- Zhejiang University
- Hangzhou 310027
- China
| | - Xiang Gao
- State Key Laboratory of Clean Energy Utilization
- Zhejiang University
- Hangzhou 310027
- China
| | - Xuesen Du
- State Key Laboratory of Clean Energy Utilization
- Zhejiang University
- Hangzhou 310027
- China
- Key Laboratory of Low-Grade Energy Utilization Technologies & Systems of the Ministry of Education of China
| | - Chenghang Zheng
- Key Laboratory of Low-Grade Energy Utilization Technologies & Systems of the Ministry of Education of China
- College of Power Engineering
- Chongqing University
- Chongqing 400044
- China
| | - Zhongyang Luo
- State Key Laboratory of Clean Energy Utilization
- Zhejiang University
- Hangzhou 310027
- China
| | - Kefa Cen
- State Key Laboratory of Clean Energy Utilization
- Zhejiang University
- Hangzhou 310027
- China
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7
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Shetty M, Murugappan K, Prasomsri T, Green WH, Román-Leshkov Y. Reactivity and stability investigation of supported molybdenum oxide catalysts for the hydrodeoxygenation (HDO) of m-cresol. J Catal 2015. [DOI: 10.1016/j.jcat.2015.07.034] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Ajay Rakkesh R, Durgalakshmi D, Balakumar S. Nanostructuring of a GNS-V2O5–TiO2 core–shell photocatalyst for water remediation applications under sun-light irradiation. RSC Adv 2015. [DOI: 10.1039/c5ra00180c] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The GNS-V2O5–TiO2 composite, as a new class of nanoarchitecture, has been successfully fabricated by a facile hydrothermal process followed by a sol–gel technique.
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Affiliation(s)
- R. Ajay Rakkesh
- National Centre for Nanoscience and Nanotechnology
- University of Madras
- Guindy campus
- Chennai 600025
- India
| | - D. Durgalakshmi
- National Centre for Nanoscience and Nanotechnology
- University of Madras
- Guindy campus
- Chennai 600025
- India
| | - S. Balakumar
- National Centre for Nanoscience and Nanotechnology
- University of Madras
- Guindy campus
- Chennai 600025
- India
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9
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Dasireddy VD, Singh S, Friedrich HB. Vanadium oxide supported on non-stoichiometric strontium hydroxyapatite catalysts for the oxidative dehydrogenation of n-octane. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcata.2014.08.044] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Effect of the Support on the Oxidation of Heptane Using Vanadium Supported on Alkaline Earth Metal Hydroxyapatites. Catal Letters 2014. [DOI: 10.1007/s10562-014-1424-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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11
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Yun D, Zhao Y, Abdullahi I, Herrera JE. The effect of interstitial nitrogen in the activity of the VOx/N-TiO2 catalytic system for ethanol partial oxidation. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcata.2014.03.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Stacchiola DJ, Senanayake SD, Liu P, Rodriguez JA. Fundamental Studies of Well-Defined Surfaces of Mixed-Metal Oxides: Special Properties of MOx/TiO2(110) {M = V, Ru, Ce, or W}. Chem Rev 2012; 113:4373-90. [DOI: 10.1021/cr300316v] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Darío J. Stacchiola
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Sanjaya D. Senanayake
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ping Liu
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - José A. Rodriguez
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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13
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Dinse A, Carrero C, Ozarowski A, Schomäcker R, Schlögl R, Dinse KP. Characterization and Quantification of Reduced Sites on Supported Vanadium Oxide Catalysts by Using High-Frequency Electron Paramagnetic Resonance. ChemCatChem 2012. [DOI: 10.1002/cctc.201100412] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Wang Y, Su YR, Qiao L, Liu LX, Su Q, Zhu CQ, Liu XQ. Synthesis of one-dimensional TiO2/V2O5 branched heterostructures and their visible light photocatalytic activity towards Rhodamine B. NANOTECHNOLOGY 2011; 22:225702. [PMID: 21454938 DOI: 10.1088/0957-4484/22/22/225702] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present the synthesis and visible-light-induced catalytic activity of one-dimensional (1D) TiO(2)/V(2)O(5) branched heterostructures. The 1D TiO(2)/V(2)O(5) heterostructures were prepared by RF reactive magnetron sputtering of V(2)O(5) onto electrospun TiO(2) nanofibers. Then, the samples were annealed at 300 °C for 2 h in air ambient to form the 1D TiO(2)/V(2)O(5) branched heterostructures. The photodecomposition rate of Rhodamine B (RhB) by the 1D TiO(2)/V(2)O(5) branched heterostructures under visible light was much faster than that of pure TiO(2) nanofibers, revealing that the visible-light-induced catalytic activity of the 1D TiO(2)/V(2)O(5) branched heterostructures was greatly improved. The enhancement of the photocatalytic activity of the 1D TiO(2)/V(2)O(5) branched heterostructures can be ascribed to the coupling with a small bandgap semiconductor material V(2)O(5), where the absorption range is extended, the photogenerated electrons and holes are highly separated and the surface charge carrier transfer rate is promoted.
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Affiliation(s)
- Y Wang
- Department of Physics, Lanzhou University, Lanzhou, People's Republic of China
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15
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Aksel S, Eder D. Catalytic effect of metal oxides on the oxidation resistance in carbon nanotube–inorganic hybrids. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/c0jm01129k] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Chary KV, Ramesh K, Naresh D, Rao PVR, Rao AR, Rao VV. The effect of zirconia polymorphs on the structure and catalytic properties of V2O5/ZrO2 catalysts. Catal Today 2009. [DOI: 10.1016/j.cattod.2008.04.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Characterization and activity of vanadia-promoted Pt/ZrO2 catalysts for the water–gas shift reaction. Catal Today 2008. [DOI: 10.1016/j.cattod.2008.05.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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19
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Chigwada TR, Chikwana E, Ruwona T, Olagunju O, Simoyi RH. S-Oxygenation of Thiocarbamides. 3. Nonlinear Kinetics in the Oxidation of Trimethylthiourea by Acidic Bromate. J Phys Chem A 2007; 111:11552-61. [PMID: 17944446 DOI: 10.1021/jp074897z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tabitha R. Chigwada
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506-6045, and Department of Chemistry, California State UniversityChico, Chico, California 95929-0210
| | - Edward Chikwana
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506-6045, and Department of Chemistry, California State UniversityChico, Chico, California 95929-0210
| | - Tinashe Ruwona
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506-6045, and Department of Chemistry, California State UniversityChico, Chico, California 95929-0210
| | - Olufunke Olagunju
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506-6045, and Department of Chemistry, California State UniversityChico, Chico, California 95929-0210
| | - Reuben H. Simoyi
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506-6045, and Department of Chemistry, California State UniversityChico, Chico, California 95929-0210
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20
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Ismail AA, Matsunaga H. Influence of vanadia content onto TiO2–SiO2 matrix for photocatalytic oxidation of trichloroethylene. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.08.075] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Rao TVM, Deo G. Ethane and Propane Oxidation over Supported V2O5/TiO2 Catalysts: Analysis of Kinetic Parameters. Ind Eng Chem Res 2006. [DOI: 10.1021/ie060715w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- T. V. Malleswara Rao
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur, 208 016, India
| | - Goutam Deo
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur, 208 016, India
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22
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Chary KV, Kumar CP, Rajiah T, Srikanth CS. Dispersion and reactivity of monolayer vanadium oxide catalysts supported on zirconia: The influence of molybdena addition. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcata.2006.05.049] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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Olagunju O, Siegel PD, Olojo R, Simoyi RH. Oxyhalogen−Sulfur Chemistry: Kinetics and Mechanism of Oxidation of N-Acetylthiourea by Chlorite and Chlorine Dioxide. J Phys Chem A 2006; 110:2396-410. [PMID: 16480299 DOI: 10.1021/jp055805d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The oxidation reactions of N-acetylthiourea (ACTU) by chlorite and chlorine dioxide were studied in slightly acidic media. The ACTU-ClO(2)(-) reaction has a complex dependence on acid with acid catalysis in pH > 2 followed by acid retardation in higher acid conditions. In excess chlorite conditions the reaction is characterized by a very short induction period followed by a sudden and rapid formation of chlorine dioxide and sulfate. In some ratios of oxidant to reductant mixtures, oligo-oscillatory formation of chlorine dioxide is observed. The stoichiometry of the reaction is 2:1, with a complete desulfurization of the ACTU thiocarbamide to produce the corresponding urea product: 2ClO(2)(-) + CH(3)CONH(NH(2))C=S + H(2)O --> CH(3)CONH(NH(2))C=O + SO(4)(2-) + 2Cl(-) + 2H(+) (A). The reaction of chlorine dioxide and ACTU is extremely rapid and autocatalytic. The stoichiometry of this reaction is 8ClO(2)(aq) + 5CH(3)CONH(NH(2))C=S + 9H(2)O --> 5CH(3)CONH(NH(2))C=O + 5SO(4)(2-) + 8Cl(-) + 18H(+) (B). The ACTU-ClO(2)(-) reaction shows a much stronger HOCl autocatalysis than that which has been observed with other oxychlorine-thiocarbamide reactions. The reaction of chlorine dioxide with ACTU involves the initial formation of an adduct which hydrolyses to eliminate an unstable oxychlorine intermediate HClO(2)(-) which then combines with another ClO(2) molecule to produce and accumulate ClO(2)(-). The oxidation of ACTU involves the successive oxidation of the sulfur center through the sulfenic and sulfinic acids. Oxidation of the sulfinic acid by chlorine dioxide proceeds directly to sulfate bypassing the sulfonic acid. Sulfonic acids are inert to further oxidation and are only oxidized to sulfate via an initial hydrolysis reaction to yield bisulfite, which is then rapidly oxidized. Chlorine dioxide production after the induction period is due to the reaction of the intermediate HOCl species with ClO(2)(-). Oligo-oscillatory behavior arises from the fact that reactions that form ClO(2) are comparable in magnitude to those that consume ClO(2), and hence the assertion of each set of reactions is based on availability of reagents that fuel them. A computer simulation study involving 30 elementary and composite reactions gave a good fit to the induction period observed in the formation of chlorine dioxide and in the autocatalytic consumption of ACTU in its oxidation by ClO(2).
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Affiliation(s)
- Olufunke Olagunju
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, USA
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24
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Kemp TJ, McIntyre RA. Transition metal-doped titanium(IV) dioxide: Characterisation and influence on photodegradation of poly(vinyl chloride). Polym Degrad Stab 2006. [DOI: 10.1016/j.polymdegradstab.2005.04.033] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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25
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Chary KV, Kumar CP, Naresh D, Bhaskar T, Sakata Y. Characterization and reactivity of Al2O3–ZrO2 supported vanadium oxide catalysts. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcata.2005.07.036] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chigwada TR, Simoyi RH. S-Oxygenation of Thiocarbamides II: Oxidation of Trimethylthiourea by Chlorite and Chlorine Dioxide. J Phys Chem A 2005; 109:1094-104. [PMID: 16833418 DOI: 10.1021/jp045650u] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The kinetics of the oxidation of a substituted thiourea, trimethylthiourea (TMTU), by chlorite have been studied in slightly acidic media. The reaction is much faster than the comparable oxidation of the unsubstituted thiourea by chlorite. The stoichiometry of the reaction was experimentally deduced to be 2ClO2- + Me2N(NHMe)C=S + H2O --> 2Cl- + Me2N(NHMe)C=O + SO4(2-) + 2H+. In excess chlorite conditions, chlorine dioxide is formed after a short induction period. The oxidation of TMTU occurs in two phases. It starts initially with S-oxygenation of the sulfur center to yield the sulfinic acid, which then reacts in the second phase predominantly through an initial hydrolysis to produce trimethylurea and the sulfoxylate anion. The sulfoxylate anion is a highly reducing species which is rapidly oxidized to sulfate. The sulfinic and sulfonic acids of TMTU exists in the form of zwitterionic species that are stable in acidic environments and rapidly decompose in basic environments. The rate of oxidation of the sulfonic acid is determined by its rate of hydrolysis, which is inhibited by acid. The direct reaction of chlorine dioxide and TMTU is autocatalytic and also inhibited by acid. It commences with the initial formation of an adduct of the radical chlorine dioxide species with the electron-rich sulfur center of the thiocarbamide followed by reaction of the adduct with another chlorine dioxide molecule and subsequent hydrolysis to yield chlorite and a sulfenic acid. The bimolecular rate constant for the reaction of chlorine dioxide and TMTU was experimentally determined as 16 +/- 3.0 M(-1) s(-1) at pH 1.00.
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Affiliation(s)
- Tabitha R Chigwada
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, USA
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Chigwada TR, Chikwana E, Simoyi RH. S-Oxygenation of Thiocarbamides I: Oxidation of Phenylthiourea by Chlorite in Acidic Media. J Phys Chem A 2005; 109:1081-93. [PMID: 16833417 DOI: 10.1021/jp0458654] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The oxidation of 1-phenyl-2-thiourea (PTU) by chlorite was studied in aqueous acidic media. The reaction is extremely complex with reaction dynamics strongly influenced by the pH of reaction medium. In excess chlorite concentrations the reaction stoichiometry involves the complete desulfurization of PTU to yield a urea residue and sulfate: 2ClO2- + PhN(H)CSNH2 + H2O --> SO4(2-) + PhN(H)CONH2 + 2Cl- + 2H+. In excess PTU, mixtures of sulfinic and sulfonic acids are formed. The reaction was followed spectrophotometrically by observing the formation of chlorine dioxide which is formed from the reaction of the reactive intermediate HOCl and chlorite: 2ClO2- + HOCl + H+ --> 2ClO2(aq) + Cl- + H2O. The complexity of the ClO2- - PTU reaction arises from the fact that the reaction of ClO2 with PTU is slow enough to allow the accumulation of ClO2 in the presence of PTU. Hence the formation of ClO2 was observed to be oligooscillatory with transient formation of ClO2 even in conditions of excess oxidant. The reaction showed complex acid dependence with acid catalysis in pH conditions higher than pKa of HClO2 and acid retardation in pH conditions of less than 2.0. The rate of oxidation of PTU was given by -d[PTU]/dt = k1[ClO2-][PTU] + k2[HClO2][PTU] with the rate law: -d[PTU]/dt = [Cl(III)](T)[PTU]0/K(a1) + [H+] [k1K(a1) + k2[H+]]; where [Cl(III)]T is the sum of chlorite and chlorous acid and K(a1) is the acid dissociation constant for chlorous acid. The following bimolecular rate constants were evaluated; k1 = 31.5+/-2.3 M(-1) s(-1) and k2 = 114+/-7 M(-1) s(-1). The direct reaction of ClO2 with PTU was autocatalytic in low acid concentrations with a stoichiometric ratio of 8:5; 8ClO2 + 5PhN(H)CSNH2 + 9H2O --> 5SO4(2-) + 5PhN(H)CONH2 + 8Cl- + 18H+. The proposed mechanism implicates HOCl as a major intermediate whose autocatalytic production determined the observed global dynamics of the reaction. A comprehensive 29-reaction scheme is evoked to describe the complex reaction dynamics.
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Affiliation(s)
- Tabitha R Chigwada
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751, USA
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Chikwana E, Otoikhian A, Simoyi RH. Oxyhalogen−Sulfur Chemistry: Kinetics and Mechanism of Oxidation of Guanylthiourea by Acidified Bromate. J Phys Chem A 2004. [DOI: 10.1021/jp045897r] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Edward Chikwana
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
| | - Adenike Otoikhian
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
| | - Reuben H. Simoyi
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
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30
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Chary KV, Reddy KR, Kumar CP, Naresh D, Rao VV, Mestl G. Characterization and reactivity of molybdenum oxide catalysts supported on Nb2O5–TiO2. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2004.01.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Chary KV, Praveen Kumar C, Venkat Ramana Rao P, Venkat Rao V. Dispersion and reactivity of V2O5 catalysts supported on Al2O3–ZrO2. CATAL COMMUN 2004. [DOI: 10.1016/j.catcom.2004.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Ma X, Gong J, Wang S, He F, Yang X, Wang G, Xu G. Characterization and reactivity of silica-supported bimetallic molybdenum and stannic oxides for the transesterification of dimethyl oxalate with phenol. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2004.04.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Darkwa J, Olojo R, Chikwana E, Simoyi RH. Antioxidant Chemistry: Oxidation of l-Cysteine and Its Metabolites by Chlorite and Chlorine Dioxide. J Phys Chem A 2004. [DOI: 10.1021/jp049748k] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James Darkwa
- Department of Chemistry, University of the Western Cape, Bellville 7535, South Africa
| | - Rotimi Olojo
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, Oregon 97207-0751
| | - Edward Chikwana
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, Oregon 97207-0751
| | - Reuben H. Simoyi
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, Oregon 97207-0751
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Ojo JF, Otoikhian A, Olojo R, Simoyi RH. Oxyhalogen−Sulfur Chemistry: Nonlinear Oxidation Kinetics of Hydroxymethanesulfinic Acid by Acidic Iodate. J Phys Chem A 2004. [DOI: 10.1021/jp037140q] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jonathan F. Ojo
- Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
| | - Adenike Otoikhian
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
| | - Rotimi Olojo
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
| | - Reuben H. Simoyi
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
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Chary KV, Ramesh K, Vidyasagar G, Venkat Rao V. Vapour phase alkylation of phenol with methanol over vanadium oxide supported on zirconia. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1169(02)00691-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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36
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37
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Rodella C, Nascente P, Franco R, Magon C, Mastelaro V, Florentino A. Surface Characterisation of V2O5/TiO2 Catalytic System. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/1521-396x(200109)187:1<161::aid-pssa161>3.0.co;2-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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38
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Chary KVR, Bhaskar T, Kishan G, Reddy KR. Characterization and Reactivity of Molybdenum Oxide Catalysts Supported on Niobia. J Phys Chem B 2001. [DOI: 10.1021/jp003201y] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Komandur V. R. Chary
- Catalysis Division, Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | - Thallada Bhaskar
- Catalysis Division, Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | - Gurram Kishan
- Catalysis Division, Indian Institute of Chemical Technology, Hyderabad 500 007, India
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Popova G, Chesalov Y, Andrushkevich T, Zakharov I, Stoyanov E. Determination of surface intermediates during the selective oxidation of formaldehyde over V–Ti–O catalyst by in situ FTIR spectroscopy. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1381-1169(00)00102-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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40
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Chary KV, Bhaskar T, Murthy MR, Seela KK, Rao VV. Ammoxidation of 3-Picoline over Vanadia-Molybdena Catalysts Supported on γ-Al 2O 3. JOURNAL OF CHEMICAL RESEARCH 2000. [DOI: 10.3184/030823400103167886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ammoxidation of 3-picoline to nicotinonitrile was carried out on V2O5-MoO3 catalysts supported on γ-alumina. The results suggest that the addition of MoO3 improves catalytic properties during ammoxidation.
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Affiliation(s)
- Komandur V.R. Chary
- Catalysis Section, Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | - Thallada Bhaskar
- Catalysis Section, Indian Institute of Chemical Technology, Hyderabad 500 007, India
| | | | | | - Vattikonda Venkat Rao
- Catalysis Section, Indian Institute of Chemical Technology, Hyderabad 500 007, India
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Affiliation(s)
- S. E. Kooi
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - A. W. Castleman
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802
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