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Damoyi NE, Friedrich HB, Kruger GH, Willock DJ. A DFT study of the catalytic ODH of n-hexane over a cluster model of vanadium oxide. MOLECULAR CATALYSIS 2023. [DOI: 10.1016/j.mcat.2023.113078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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2
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Cao Y, Ran R, Wu X, Si Z, Kang F, Weng D. Progress on metal-support interactions in Pd-based catalysts for automobile emission control. J Environ Sci (China) 2023; 125:401-426. [PMID: 36375925 DOI: 10.1016/j.jes.2022.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 12/30/2021] [Accepted: 01/06/2022] [Indexed: 06/16/2023]
Abstract
The interactions between metals and oxide supports, so-called metal-support interactions (MSI), are of great importance in heterogeneous catalysis. Pd-based automotive exhaust control catalysts, especially Pd-based three-way catalysts (TWCs), have received considerable research attention owing to its prominent oxidation activity of HCs/CO, as well as excellent thermal stability. For Pd-based TWCs, the dispersion, chemical state and thermal stability of Pd species, which are crucial to the catalytic performance, are closely associated with interactions between metal nanoparticles and their supporting matrix. Progress on the research about MSI and utilization of MSI in advanced Pd-based three-way catalysts are reviewed here. Along with the development of advanced synthesis approaches and engine control technology, the study on MSI would play a notable role in further development of catalysts for automobile exhaust control.
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Affiliation(s)
- Yidan Cao
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.
| | - Rui Ran
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Xiaodong Wu
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Zhichun Si
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Feiyu Kang
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Duan Weng
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
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3
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Sun J, Yi J, Cheng L. Directional Monte Carlo Lattice Search Algorithm for the Structure Search of Alumina Clusters (Al2O3)n (n=1~50). ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21050207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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4
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Shi D, Wang H, Kovarik L, Gao F, Wan C, Hu JZ, Wang Y. WO supported on γ-Al2O3 with different morphologies as model catalysts for alkanol dehydration. J Catal 2018. [DOI: 10.1016/j.jcat.2018.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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5
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Otake KI, Cui Y, Buru CT, Li Z, Hupp JT, Farha OK. Single-Atom-Based Vanadium Oxide Catalysts Supported on Metal-Organic Frameworks: Selective Alcohol Oxidation and Structure-Activity Relationship. J Am Chem Soc 2018; 140:8652-8656. [PMID: 29950097 DOI: 10.1021/jacs.8b05107] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We report the syntheses, structures, and oxidation catalytic activities of a single-atom-based vanadium oxide incorporated in two highly crystalline MOFs, Hf-MOF-808 and Zr-NU-1000. These vanadium catalysts were introduced by a postsynthetic metalation, and the resulting materials (Hf-MOF-808-V and Zr-NU-1000-V) were thoroughly characterized through a combination of analytic and spectroscopic techniques including single-crystal X-ray crystallography. Their catalytic properties were investigated using the oxidation of 4-methoxybenzyl alcohol under an oxygen atmosphere as a model reaction. Crystallographic and variable-temperature spectroscopic studies revealed that the incorporated vanadium in Hf-MOF-808-V changes position with heat, which led to improved catalytic activity.
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Affiliation(s)
- Ken-Ichi Otake
- Department of Chemistry and Chemical and Biological Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Yuexing Cui
- Department of Chemistry and Chemical and Biological Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Cassandra T Buru
- Department of Chemistry and Chemical and Biological Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Zhanyong Li
- Department of Chemistry and Chemical and Biological Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Joseph T Hupp
- Department of Chemistry and Chemical and Biological Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States
| | - Omar K Farha
- Department of Chemistry and Chemical and Biological Engineering , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States.,Department of Chemistry, Faculty of Science , King Abdulaziz University , Jeddah 21589 , Saudi Arabia
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6
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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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7
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8
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Vanadium oxide nanostructures on another oxide: The viewpoint from model catalysts studies. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.12.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Tang Z, Wang S, Zhang L, Ding D, Chen M, Wan H. Effects of O2 pressure on the oxidation of VOx/Pt(111). Phys Chem Chem Phys 2013; 15:12124-31. [DOI: 10.1039/c3cp50712b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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10
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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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Beck B, Harth M, Hamilton NG, Carrero C, Uhlrich JJ, Trunschke A, Shaikhutdinov S, Schubert H, Freund HJ, Schlögl R, Sauer J, Schomäcker R. Partial oxidation of ethanol on vanadia catalysts on supporting oxides with different redox properties compared to propane. J Catal 2012. [DOI: 10.1016/j.jcat.2012.09.008] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Structural determination of (Al2O3)n (n=1–7) clusters based on density functional calculation. COMPUT THEOR CHEM 2012. [DOI: 10.1016/j.comptc.2012.07.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Reversible oxidation of WOx and MoOx nano phases. Catal Today 2012. [DOI: 10.1016/j.cattod.2011.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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14
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Dong L, Zhang L, Sun C, Yu W, Zhu J, Liu L, Liu B, Hu Y, Gao F, Dong L, Chen Y. Study of the Properties of CuO/VOx/Ti0.5Sn0.5O2 Catalysts and Their Activities in NO + CO Reaction. ACS Catal 2011. [DOI: 10.1021/cs200045f] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lihui Dong
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Lingling Zhang
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Chuanzhi Sun
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Wujiang Yu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Jie Zhu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Lianjun Liu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Bin Liu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Yuhai Hu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Fei Gao
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Lin Dong
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
| | - Yi Chen
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering and ‡Center of Modern Analysis, Nanjing University, Nanjing, 210093, P. R. China
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Nilius N, Risse T, Schauermann S, Shaikhutdinov S, Sterrer M, Freund HJ. Model Studies in Catalysis. Top Catal 2011. [DOI: 10.1007/s11244-011-9626-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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17
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Rodriguez JA, Stacchiola D. Catalysis and the nature of mixed-metal oxides at the nanometer level: special properties of MOx/TiO2(110) {M= V, W, Ce} surfaces. Phys Chem Chem Phys 2010; 12:9557-65. [DOI: 10.1039/c003665j] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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18
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Schmal M, Freund HJ. Towards an atomic level understanding of niobia based catalysts and catalysis by combining the science of catalysis with surface science. AN ACAD BRAS CIENC 2009. [DOI: 10.1590/s0001-37652009000200016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The science of catalysis and surface science have developed, independently, key information for understanding catalytic processes. One might argue: is there anything fundamental to be discovered through the interplay between catalysis and surface science? Real catalysts of monometallic and bimetallic Co/Nb2O5 and Pd-Co/Nb2O5 catalysts showed interesting selectivity results on the Fischer-Tropsch synthesis (Noronha et al. 1996, Rosenir et al. 1993). The presence of a noble metal increased the C+5 selectivity and decreased the methane formation depending of the reduction temperature. Model catalyst of Co-Pd supported on niobia and alumina were prepared and characterized at the atomic level, thus forming the basis for a comparison with "real" support materials. Growth, morphology and structure of both pure metal and alloy particles were studied. It is possible to support the strong metal support interaction suggested by studies on real catalysts via the investigation of model systems for niobia in comparison to alumina support in which this effect does not occur. Formation of Co2+ penetration into the niobia lattice was suggested on the basis of powder studies and can be fully supported on the basis of model studies. It is shown for both real catalysts and model systems that oxidation state of Co plays a key role in controlling the reactivity in Fischer-Tropsch reactions systems and that the addition of Pd is a determining factor for the stability of the catalyst. It is demonstrated that the interaction with unsaturated hydrocarbons depends strongly on the state of oxidation.
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Muylaert I, Van Der Voort P. Supported vanadium oxide in heterogeneous catalysis: elucidating the structure–activity relationship with spectroscopy. Phys Chem Chem Phys 2009; 11:2826-32. [DOI: 10.1039/b819808j] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Choi J, Shin CB, Suh DJ. Polyvanadate dominant vanadia–alumina composite aerogels prepared by a non-alkoxide sol–gel method. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b905435a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Fortrie R, Todorova TK, Ganduglia-Pirovano MV, Sauer J. Nonuniform temperature dependence of the reactivity of disordered VOx/κ-Al2O3(001) surfaces: A density functional theory based Monte Carlo study. J Chem Phys 2008; 129:224710. [DOI: 10.1063/1.3021290] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sierka M, Döbler J, Sauer J, Santambrogio G, Brümmer M, Wöste L, Janssens E, Meijer G, Asmis KR. Unexpected Structures of Aluminum Oxide Clusters in the Gas Phase. Angew Chem Int Ed Engl 2007; 46:3372-5. [PMID: 17385778 DOI: 10.1002/anie.200604823] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Marek Sierka
- Institut für Chemie, Humboldt-Universität zu Berlin, Berlin, Germany.
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25
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Sierka M, Döbler J, Sauer J, Santambrogio G, Brümmer M, Wöste L, Janssens E, Meijer G, Asmis K. Unerwartete Strukturen von Aluminiumoxidclustern in der Gasphase. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200604823] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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Kim J, Bondarchuk O, Kay BD, White J, Dohnálek Z. Preparation and characterization of monodispersed WO3 nanoclusters on TiO2(110). Catal Today 2007. [DOI: 10.1016/j.cattod.2006.07.050] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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27
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Bondarchuk O, Huang X, Kim J, Kay BD, Wang LS, White JM, Dohnálek Z. Formation of Monodisperse (WO3)3 Clusters on TiO2(110). Angew Chem Int Ed Engl 2006; 45:4786-9. [PMID: 16795101 DOI: 10.1002/anie.200600837] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Oleksandr Bondarchuk
- Center for Materials Chemistry, Texas Materials Institute, University of Texas, Austin, TX 78712, USA
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Bondarchuk O, Huang X, Kim J, Kay BD, Wang LS, White JM, Dohnálek Z. Formation of Monodisperse (WO3)3 Clusters on TiO2(110). Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200600837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Todorova TK, Ganduglia-Pirovano MV, Sauer J. Vanadium Oxides on Aluminum Oxide Supports. 1. Surface Termination and Reducibility of Vanadia Films on α-Al2O3(0001). J Phys Chem B 2005; 109:23523-31. [PMID: 16375327 DOI: 10.1021/jp053899l] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Using density functional theory and statistical thermodynamics, we obtained the phase diagram of thin VnOm films of varying thickness (approximately 2-6 A, 1-6 vanadium layers) supported on alpha-Al2O3(0001). Depending on the temperature, oxygen pressure, and vanadium concentration, films with different thickness and termination may form. In ultrahigh vacuum (UHV), at room temperature and for low vanadium concentrations, an ultrathin (1 x 1) O=V-terminated film is most stable. As more vanadium is supplied, the thickest possible films form. Their structures and terminations correspond to previous findings for the (0001) surface of bulk V2O3 [Kresse et al., Surf. Sci. 2004, 555, 118]. The presence of surface vanadyl (O=V) groups is a prevalent feature. They are stable up to at least 800 K in UHV. Vanadyl oxygen atoms induce a V(2p) core-level shift of about 2 eV on the surface V atoms. The reducibility of the supported films is characterized by the energy of oxygen defect formation. For the stable structures, the results vary between 4.11 and 3.59 eV per 1/2O2. In contrast, oxygen removal from the V2O5(001) surface is much easier (1.93 eV). This provides a possible explanation for the lower catalytic activity of vanadium oxides supported on alumina compared to that of crystalline vanadia particles.
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Affiliation(s)
- Tanya K Todorova
- Humboldt-Universität zu Berlin, Institut für Chemie, Unter den Linden 6, D-10099 Berlin, Germany
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Brázdová V, Ganduglia-Pirovano MV, Sauer J. Vanadium Oxides on Aluminum Oxide Supports. 2. Structure, Vibrational Properties, and Reducibility of V2O5 Clusters on α-Al2O3(0001). J Phys Chem B 2005; 109:23532-42. [PMID: 16375328 DOI: 10.1021/jp0539167] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure, stability, and vibrational properties of isolated V2O5 clusters on the Al2O3(0001) surface have been studied by density functional theory and statistical thermodynamics. The most stable structure does not possess vanadyl oxygen atoms. The positions of the oxygen atoms are in registry with those of the alumina support, and both vanadium atoms occupy octahedral sites. Another structure with one vanadyl oxygen atom is only 0.12 eV less stable. Infrared spectra are calculated for the two structures. The highest frequency at 922 cm(-1) belongs to a V-O stretch in the V-O-Al interface bonds, which supports the assignment of such a mode to the band observed around 941 cm(-1) for vanadia particles on alumina. Removal of a bridging oxygen atom from the most stable cluster at the V-O-Al interface bond costs 2.79 eV. Removal of a (vanadyl) oxygen atom from a thin vanadia film on alpha-Al2O3 costs 1.3 eV more, but removal from a V2O5(001) single-crystal surface costs 0.9 eV less. Similar to the V2O5(001) surface, the facile reduction is due to substantial structure relaxations that involve formation of an additional V-O-V bond and yield a pair of V(IV)(d1) sites instead of a V(III)(d2)/V(V)(d0) pair.
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Affiliation(s)
- Veronika Brázdová
- Humboldt-Universität zu Berlin, Institut für Chemie, Unter den Linden 6, D-10099 Berlin, Germany
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Döbler J, Pritzsche M, Sauer J. Oxidation of Methanol to Formaldehyde on Supported Vanadium Oxide Catalysts Compared to Gas Phase Molecules. J Am Chem Soc 2005; 127:10861-8. [PMID: 16076191 DOI: 10.1021/ja051720e] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxidation of methanol to formaldehyde on silica supported vanadium oxide is studied by density functional theory. For isolated vanadium oxide species silsesquioxane-type models are adopted. The first step is dissociative adsorption of methanol yielding CH3O(O=)V(O-)2 surface complexes. This makes the O=V(OCH3)3 molecule a suited model system. The rate-limiting oxidation step involves hydrogen transfer from the methoxy group to the vanadyl oxygen atom. The transition state is biradicaloid and needs to be treated by the broken-symmetry approach. The activation energies for O=V(OCH3)3 and the silsesquioxane surface model are 147 and 154 kJ/mol. In addition, the (O=V(OCH3)3)(2) dimer (a model for polymeric vanadium oxide species) and the O=V(OCH3)3(*+) radical cation are studied. For the latter the barrier is only 80 kJ/mol, indicating a strong effect of the charge on the energy profile of the reaction and questioning the significance of gas-phase cluster studies for understanding the activity of supported oxide catalysts.
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Affiliation(s)
- Jens Döbler
- Institut für Chemie der Humboldt Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
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Keller DE, de Groot FMF, Koningsberger DC, Weckhuysen BM. ΛO4 Upside Down: A New Molecular Structure for Supported VO4 Catalysts. J Phys Chem B 2005; 109:10223-33. [PMID: 16852239 DOI: 10.1021/jp044539l] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vanadium oxide (1 wt %) supported on gamma-Al(2)O(3) was used to investigate the interface between the catalytically active species and the support oxide. Raman, UV-vis-NIR DRS, ESR, XANES, and EXAFS were used to characterize the sample in great detail. All techniques showed that an isolated VO(4) species was present at the catalyst surface, which implies that no V-O-V moiety is present. Surprisingly, a Raman band was present at 900 cm(-1), which is commonly assigned to a V-O-V vibration. This observation contradicts the current literature assignment. To further elucidate on potential other Raman assignments, the exact molecular structure of the VO(4) entity (1 V=O bond of 1.58 A and 3 V-O bonds of 1.72 A) together with its position relative to the support O anions and Al cation of the Al(2)O(3) support has been investigated with EXAFS. In combination with a structural model of the alumina surface, the arrangement of the support atoms in the proximity of the VO(4) entity could be clarified, leading to a new molecular structure of the interface between VO(4) and Al(2)O(3). It was found that VO(4) is anchored to the support oxide surface, with only one V-O support bond instead of three, which is commonly accepted in the literature. The structural model suggested in this paper leaves three possible assignments for the 900 cm(-1) band: a V-O-Al vibration, a V-O-H vibration, and a V-(O-O) vibration. The pros and cons of these different options will be discussed.
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Affiliation(s)
- Daphne E Keller
- Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, PO Box 80083, 3508 TB Utrecht, The Netherlands
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Wu Z, Kim HS, Stair PC, Rugmini S, Jackson SD. On the Structure of Vanadium Oxide Supported on Aluminas: UV and Visible Raman Spectroscopy, UV−Visible Diffuse Reflectance Spectroscopy, and Temperature-Programmed Reduction Studies. J Phys Chem B 2005; 109:2793-800. [PMID: 16851289 DOI: 10.1021/jp046011m] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vanadia species on aluminas (delta- and gamma-Al2O3) with surface VOx density in the range 0.01-14.2 V/nm2 have been characterized by UV and visible Raman spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and temperature-programmed reduction in hydrogen. It is shown that the alumina phase has little influence on the structure and reducibility of surface VOx species under either dehydrated or hydrated conditions. Three similar types of dispersed VOx species, i.e., monovanadates, polyvanadates, and V2O5, are identified on both aluminas under dehydrated conditions. Upon hydration, polymerized VOx species dominate on the surfaces of the two aluminas. The broad Raman band at around 910 cm(-1), observed on dehydrated V/delta-, gamma-Al2O3 at all V loadings (0.01-14.2 V/nm2), is assigned to the interface mode (V-O-Al) instead of the conventionally assigned V-O-V bond. The direct observation of the interface bond is of significance for the understanding of redox catalysis because this bond has been considered to be the key site in oxidation reactions catalyzed by supported vanadia. Two types of frequency shifts of the V=O stretching band (1013-1035 cm(-1)) have been observed in the Raman spectra of V/Al2O3: a shift as a function of surface VOx density and a shift as a function of excitation wavelength. The shift of the V=O band to higher wavenumbers with increasing surface VOx density is due to the change of VOx structure. The V=O stretching band in dispersed vanadia always appears at lower wavenumber in UV Raman spectra than in visible Raman spectra for the same V/Al2O3 sample. This shift is explained by selective resonance enhancement according to the UV-Vis DRS results. It implies that UV Raman has higher sensitivity to isolated and less polymerized VOx species while visible Raman is more sensitive to highly polymerized VOx species and crystalline V2O5. These results show that a multiwavelength excitation approach provides a more complete structural characterization of supported VOx catalysts.
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Affiliation(s)
- Zili Wu
- Department of Chemistry, Center for Catalysis and Surface Science and Institute of Environmental Catalysis, Northwestern University, Evanston, Illinois 60208, USA
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Moisii C, Curran MD, van de Burgt LJ, Stiegman AE. Raman spectroscopy of discrete silica supported vanadium oxide: assignment of fundamental stretching modes. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b505661f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Brázdová V, Ganduglia-Pirovano MV, Sauer J. Crystal Structure and Vibrational Spectra of AlVO4. A DFT Study. J Phys Chem B 2004; 109:394-400. [PMID: 16851028 DOI: 10.1021/jp046055v] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present periodic density functional calculations within the generalized gradient approximation (Perdew-Wang 91) on structure and vibrational properties of bulk AlVO(4). The optimized structure agrees well with crystallographic data obtained by Rietveld refinement (the mean absolute deviation of bond distances is 0.032 A), but the deviations are larger for the lighter oxygen atoms than for the heavier Al and V atoms. All observed bands in the Raman and IR spectrum have been assigned to calculated harmonic frequencies. Bands in the 1020-900 cm(-1) region have been assigned to V-O((2)) stretches in V-O((2))-Al bonds. The individual bands do not arise from vibrations of only one bond, not even from vibrations of several bonds of one VO(4) tetrahedron. The results confirm that vibrations around 940 cm(-1) observed for vanadia particles supported on thin alumina film are V-O-Al interface modes with 2-fold coordinated oxygen atoms in the V-O((2))-Al interface bonds.
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Affiliation(s)
- Veronika Brázdová
- Humboldt Universität zu Berlin, Institut für Chemie, Unter den Linden 6, D-10099 Berlin, Germany
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Justes DR, Moore NA, Castleman AW. Reactions of Vanadium and Niobium Oxides with Methanol. J Phys Chem B 2004. [DOI: 10.1021/jp031152u] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- D. R. Justes
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - N. A. Moore
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - A. W. Castleman
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802
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Magg N, Giorgi JB, Frank MM, Immaraporn B, Schroeder T, Bäumer M, Freund HJ. Alumina-Supported Vanadium Nanoparticles: Structural Characterization and CO Adsorption Properties. J Am Chem Soc 2004; 126:3616-26. [PMID: 15025491 DOI: 10.1021/ja039278s] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Alumina-supported vanadium particles were prepared under ultrahigh vacuum (UHV) conditions and characterized with respect to their structural and CO adsorption properties. As supporting oxide, we used a thin, well-ordered alumina film grown on NiAl(110). This allows the application of scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRAS), and X-ray photoelectron spectroscopy (XPS) without charging effects. Vanadium evaporation under UHV conditions leads to the growth of nanometer-sized particles which strongly interact with the alumina support. At very low vanadium coverages, these particles are partially incorporated into the alumina film and get oxidized through the contact to alumina. Low-temperature CO adsorption in this coverage regime permits the preparation of isolated vanadium carbonyls, of which we have identified mono-, di-, and tricarbonyls of the V(CO)(y)() type. A charge-frequency relationship was set up which allows one to quantify the extent of charge transfer from vanadium to alumina. It turns out that this charge transfer depends on the V nucleation site.
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Affiliation(s)
- Norbert Magg
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
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Sauer J, Dobler J. Structure and reactivity of V2O5: bulk solid, nanosized clusters, species supported on silica and alumina, cluster cations and anions. Dalton Trans 2004:3116-21. [PMID: 15452641 DOI: 10.1039/b402873b] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Vanadyl bond dissociation energies are calculated by density functional theory (DFT). While the hybrid (B3LYP) functional results are close to the available reference data, gradient corrected functionals (BP86, PBE) yield large errors (about 50 to 100 kJ mol(-1)), but reproduce trends correctly. PBE calculations on a V(20)O(62)H(24) cluster model for the (001) surface of V(2)O(5) crystals virtually reproduce periodic slab calculations. The low bond dissociation energy (formation of oxygen surface defect) of 113 kJ mol(-1)(B3LYP) is due to substantial structure relaxations leading to formation of V-O-V bonds between the V(2)O(5) layers of the crystal. This relaxation cannot occur in polyhedral (V(2)O(5))(n) clusters and also not for V(2)O(5) species supported on silica or alumina (represented by cage-type models) for which bond dissociation energies of 250-300 kJ mol(-1) are calculated. The OV(OCH(3))(3) molecule and its dimer are also considered. Radical cations V(2)O(5)(+) and V(4)O(10)(+) have very low bond dissociation energies (22 and 14 kJ mol(-1), respectively), while the corresponding radical anions have higher dissociation energies (about 330 kJ mol(-1)) than the neutral clusters. The bond dissociation energies of the closed shell V(3)O(7)(+) cation (165 kJ mol(-1)) and the closed shell V(3)O(8)(-) anion (283 kJ mol(-1)) are closest to the values of the neutral clusters. This makes them suitable for gas phase studies which aim at comparisons with V(2)O(5) species on supporting oxides.
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Affiliation(s)
- Joachim Sauer
- Institut fur Chemie, Humboldt-Universitat zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
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Magg N, Giorgi JB, Hammoudeh A, Schroeder T, Bäumer M, Freund HJ. Model Catalyst Studies on Vanadia Particles Deposited onto a Thin-Film Alumina Support. 2. Interaction with Carbon Monoxide. J Phys Chem B 2003. [DOI: 10.1021/jp030091x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Norbert Magg
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Javier B. Giorgi
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Ayman Hammoudeh
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Thomas Schroeder
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Marcus Bäumer
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Hans-Joachim Freund
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
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