1
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Ha JH. Aging and depth profiling of inhomogeneities and interactions of CO molecules on sputtered Pt film using ATR IR spectroscopy with lineshape analysis. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.136968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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2
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Ren X, Gobrogge EA, Lundgren CA. Titrating Pt Surface with CO Molecules. J Phys Chem Lett 2019; 10:6306-6315. [PMID: 31518134 DOI: 10.1021/acs.jpclett.9b01789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Identification and quantification of the surface sites on Pt nanoparticles are essential for developing more active electrocatalysts for many practical devices such as fuel cells and electrochemical fuel generators. In this work, we studied CO adsorption from dissolved CO in an H2SO4 electrolyte solution on a polycrystalline Pt film electrode held at a constant potential in the underpotential hydrogen deposition region using in situ attenuated total reflectance-surface-enhanced IR absorption spectroscopy (ATR-SEIRAS). Slowing down the adsorption rate by limiting the CO addition rate to the solution allows the individual CO molecules arriving at the Pt surface to rearrange, move to, and occupy their most energetically favorable sites. By using ATR-SEIRAS spectroscopy to follow the stepwise CO adsorption process, one can identify and quantify the Pt surface sites along with uncovering the CO adsorption energetic sequence. This method of slow CO adsorption on the Pt surface is analogous to the chemical titrations used for quantitative chemical analyses.
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Affiliation(s)
- X Ren
- U.S. CCDC Army Research Laboratory , Adelphi , Maryland 20783 , United States
| | - E A Gobrogge
- U.S. CCDC Army Research Laboratory , Adelphi , Maryland 20783 , United States
| | - C A Lundgren
- U.S. CCDC Army Research Laboratory , Adelphi , Maryland 20783 , United States
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3
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Kato M, Ogura K, Nakagawa S, Tokuda S, Takahashi K, Nakamura T, Yagi I. Enhancement of Electrocatalytic Oxygen Reduction Activity and Durability of Pt-Ni Rhombic Dodecahedral Nanoframes by Anchoring to Nitrogen-Doped Carbon Support. ACS OMEGA 2018; 3:9052-9059. [PMID: 31459039 PMCID: PMC6644736 DOI: 10.1021/acsomega.8b01373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 07/30/2018] [Indexed: 06/10/2023]
Abstract
Pt-based nanostructured electrocatalysts supported on carbon black have been widely studied for the oxygen reduction reaction (ORR), which occurs at the cathode in polymer electrolyte fuel cells. Because sluggish ORR kinetics are known to govern the cell performance, there is a need to develop highly active and durable electrocatalysts. The ORR activity of Pt-based electrocatalysts can be improved by controlling their morphology and alloying Pt with transition metals such as Ni. Improving the catalyst durability remains challenging and there is a lack of catalyst design concepts and synthetic strategies. We report the enhancement of the ORR activity and durability of a nanostructured Pt-Ni electrocatalyst by strong metal/support interactions with a nitrogen-doped carbon (NC) support. Pt-Ni rhombic dodecahedral nanoframes (NFs) were immobilized on the NC support and showed higher ORR electrocatalytic activity and durability in acidic media than that supported on a nondoped carbon black. Durability tests demonstrated that NF/NC showed almost no activity loss even after 50 000 potential cycles under catalytic conditions, and the Ni dissolution from the NFs was suppressed at the NC support, as confirmed by energy dispersive X-ray spectroscopy analysis. Physicochemical measurements including surface-enhanced infrared absorption spectroscopy of surface-adsorbed CO revealed that the strong metal/support interactions of the NF with the NC support caused the downshift of the d-band center position of the surface Pt. Our findings demonstrate that tuning the electronic structure of nanostructured Pt alloy electrocatalysts via the strong metal/support interactions with heteroatom-doped carbon supports will allow the development of highly active and robust electrocatalysts.
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Affiliation(s)
- Masaru Kato
- Faculty
of Environmental Earth Science and Graduate School of Environmental
Science, Hokkaido University, N10W5, Kita-ku, Sapporo 060-0810, Japan
| | - Kazuya Ogura
- Faculty
of Environmental Earth Science and Graduate School of Environmental
Science, Hokkaido University, N10W5, Kita-ku, Sapporo 060-0810, Japan
| | - Shogo Nakagawa
- Faculty
of Environmental Earth Science and Graduate School of Environmental
Science, Hokkaido University, N10W5, Kita-ku, Sapporo 060-0810, Japan
| | - Shoichi Tokuda
- Faculty
of Environmental Earth Science and Graduate School of Environmental
Science, Hokkaido University, N10W5, Kita-ku, Sapporo 060-0810, Japan
| | - Kiyonori Takahashi
- Research
Institute for Electronic Science, Hokkaido
University, N20W10, Kita-ku, Sapporo 001-0020, Japan
| | - Takayoshi Nakamura
- Research
Institute for Electronic Science, Hokkaido
University, N20W10, Kita-ku, Sapporo 001-0020, Japan
| | - Ichizo Yagi
- Faculty
of Environmental Earth Science and Graduate School of Environmental
Science, Hokkaido University, N10W5, Kita-ku, Sapporo 060-0810, Japan
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4
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McPherson IJ, Ash PA, Jones L, Varambhia A, Jacobs RMJ, Vincent KA. Electrochemical CO Oxidation at Platinum on Carbon Studied through Analysis of Anomalous in Situ IR Spectra. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:17176-17187. [PMID: 28845207 PMCID: PMC5563840 DOI: 10.1021/acs.jpcc.7b02166] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 07/21/2017] [Indexed: 05/29/2023]
Abstract
The oxidation of adsorbed CO is a key reaction in electrocatalysis. It has been studied extensively on both extended model surfaces and on nanoparticles; however, correlation between the two is far from simple. Molecular insight into the reaction is often provided using in situ IR spectroscopy; however, practical challenges mean in situ studies on nanoparticles have yet to provide the same level of detail as those on model surfaces. Here we use a new approach to in situ IR spectroscopy to study the mechanism of CO adlayer oxidation on a commercial carbon-supported Pt catalyst. We observe bipolar IR absorption bands but develop a simple model to enable fitting. Quantitative analysis of band behavior during the oxidation prepeak using the model agrees well with previous analysis based on conventional absorption bands. A second linear CO band is observed during the main oxidation region and is assigned to the distinct contribution of CO on step as opposed to terrace sites. Analysis of the step and terrace CO bands during oxidation shows that oxidation begins on the terraces of the nanoparticles before CO on steps is removed. Further correlation of this behavior with the current shows that step CO is only lost in the first of the two main oxidation peaks.
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Affiliation(s)
- Ian J. McPherson
- Department
of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
| | - Philip A. Ash
- Department
of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
| | - Lewys Jones
- Department
of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, U.K.
| | - Aakash Varambhia
- Department
of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH, U.K.
| | - Robert M. J. Jacobs
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Kylie A. Vincent
- Department
of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
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5
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UCHIDA H. Research and Development of Highly Active and Durable Electrocatalysts Based on Multilateral Analyses of Fuel Cell Reactions. ELECTROCHEMISTRY 2017. [DOI: 10.5796/electrochemistry.85.526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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6
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Effect of an Sb-Doped SnO2 Support on the CO-Tolerance of Pt2Ru3 Nanocatalysts for Residential Fuel Cells. Catalysts 2016. [DOI: 10.3390/catal6090139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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7
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Nesselberger M, Arenz M. In Situ FTIR Spectroscopy: Probing the Electrochemical Interface during the Oxygen Reduction Reaction on a Commercial Platinum High-Surface-Area Catalyst. ChemCatChem 2016. [DOI: 10.1002/cctc.201501193] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Markus Nesselberger
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Ø Copenhagen Denmark
| | - Matthias Arenz
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 2100 Ø Copenhagen Denmark
- Department of Chemistry and Biochemistry; University of Bern; Freiestrasse 3012 Bern Switzerland
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8
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Influence of structural parameters on the reaction of low temperature ethanol steam reforming over Pt/Al2O3 catalysts. Catal Today 2015. [DOI: 10.1016/j.cattod.2014.12.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Han OH. Nuclear magnetic resonance investigations on electrochemical reactions of low temperature fuel cells operating in acidic conditions. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 72:1-41. [PMID: 23731860 DOI: 10.1016/j.pnmrs.2013.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 01/10/2013] [Indexed: 06/02/2023]
Affiliation(s)
- Oc Hee Han
- Daegu Center, Korea Basic Science Institute, Daegu 702-701, Republic of Korea.
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10
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Nesselberger M, Ashton SJ, Wiberg GKH, Arenz M. Design, development, and demonstration of a fully LabVIEW controlled in situ electrochemical Fourier transform infrared setup combined with a wall-jet electrode to investigate the electrochemical interface of nanoparticulate electrocatalysts under reaction conditions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:074103. [PMID: 23902087 DOI: 10.1063/1.4816826] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present a detailed description of the construction of an in situ electrochemical ATR-FTIR setup combined with a wall-jet electrode to investigate the electrocatalytic properties of nanoparticulate catalysts in situ under controlled mass transport conditions. The presented setup allows the electrochemical interface to be probed in combination with the simultaneous determination of reaction rates. At the same time, the high level of automation allows it to be used as a standard tool in electrocatalysis research. The performance of the setup was demonstrated by probing the oxygen reduction reaction on a platinum black catalyst in sulfuric electrolyte.
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Affiliation(s)
- Markus Nesselberger
- Department of Chemistry and Nano-Science Center, University of Copenhagen, Universitetsparken 5, 2100 Ø Copenhagen, Denmark.
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11
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PtSnNi/C nanoparticle electrocatalysts for the ethanol oxidation reaction: Ni stability study. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.02.054] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Inukai J, Tryk DA, Abe T, Wakisaka M, Uchida H, Watanabe M. Direct STM Elucidation of the Effects of Atomic-Level Structure on Pt(111) Electrodes for Dissolved CO Oxidation. J Am Chem Soc 2013; 135:1476-90. [DOI: 10.1021/ja309886p] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Junji Inukai
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu, 400-0021,
Japan
| | - Donald A. Tryk
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu, 400-0021,
Japan
| | - Takahiro Abe
- Interdisciplinary
Graduate School
of Medicine and Engineering, University of Yamanashi, 4-3 Takeda, Kofu 400-8511, Japan
| | - Mitsuru Wakisaka
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu, 400-0021,
Japan
| | - Hiroyuki Uchida
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu, 400-0021,
Japan
- Clean Energy Research Center, University of Yamanashi, 4 Takeda, Kofu 400-8510, Japan
| | - Masahiro Watanabe
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu, 400-0021,
Japan
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13
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Coutanceau C, Lamy C, Urchaga P, Baranton S. Platinum Activity for CO Electrooxidation: from Single Crystal Surfaces to Nanosurfaces and Real Fuel Cell Nanoparticles. Electrocatalysis (N Y) 2012. [DOI: 10.1007/s12678-012-0089-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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14
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Electroless deposition of ultrathin Au film for surface enhanced in situ spectroelectrochemisrty and reaction-driven surface reconstruction for oxygen reduction reaction. Catal Today 2012. [DOI: 10.1016/j.cattod.2011.08.052] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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15
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Sato T, Okaya K, Kunimatsu K, Yano H, Watanabe M, Uchida H. Effect of Particle Size and Composition on CO-Tolerance at Pt–Ru/C Catalysts Analyzed by In Situ Attenuated Total Reflection FTIR Spectroscopy. ACS Catal 2012. [DOI: 10.1021/cs200550t] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takako Sato
- Interdisciplinary
Graduate School of Medicine and Engineering, ‡Fuel Cell Nanomaterials Center, and §Clean Energy Research
Center, University of Yamanashi, Takeda 4, Kofu, 400-8510, Japan
| | - Kazuki Okaya
- Interdisciplinary
Graduate School of Medicine and Engineering, ‡Fuel Cell Nanomaterials Center, and §Clean Energy Research
Center, University of Yamanashi, Takeda 4, Kofu, 400-8510, Japan
| | - Keiji Kunimatsu
- Interdisciplinary
Graduate School of Medicine and Engineering, ‡Fuel Cell Nanomaterials Center, and §Clean Energy Research
Center, University of Yamanashi, Takeda 4, Kofu, 400-8510, Japan
| | - Hiroshi Yano
- Interdisciplinary
Graduate School of Medicine and Engineering, ‡Fuel Cell Nanomaterials Center, and §Clean Energy Research
Center, University of Yamanashi, Takeda 4, Kofu, 400-8510, Japan
| | - Masahiro Watanabe
- Interdisciplinary
Graduate School of Medicine and Engineering, ‡Fuel Cell Nanomaterials Center, and §Clean Energy Research
Center, University of Yamanashi, Takeda 4, Kofu, 400-8510, Japan
| | - Hiroyuki Uchida
- Interdisciplinary
Graduate School of Medicine and Engineering, ‡Fuel Cell Nanomaterials Center, and §Clean Energy Research
Center, University of Yamanashi, Takeda 4, Kofu, 400-8510, Japan
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16
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Brimaud S, Jusys Z, Behm RJ. Controlled Surface Structure for In Situ ATR-FTIRS Studies Using Preferentially Shaped Pt Nanocrystals. Electrocatalysis (N Y) 2011. [DOI: 10.1007/s12678-011-0040-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Interactions between interfacial water and CO adsorbed on Pt and Pt–Ru alloy surfaces under electrochemical conditions: Density-functional theory study. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.09.074] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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19
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Chen A, Holt-Hindle P. Platinum-Based Nanostructured Materials: Synthesis, Properties, and Applications. Chem Rev 2010; 110:3767-804. [DOI: 10.1021/cr9003902] [Citation(s) in RCA: 1154] [Impact Index Per Article: 82.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aicheng Chen
- Department of Chemistry, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
| | - Peter Holt-Hindle
- Department of Chemistry, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada
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20
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Yamazaki SI, Yamada Y, Takeda S, Goto M, Ioroi T, Siroma Z, Yasuda K. Effects of p-substituents on electrochemical COoxidation by Rh porphyrin-based catalysts. Phys Chem Chem Phys 2010; 12:8968-76. [DOI: 10.1039/b925413g] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Rivallan M, Seguin E, Thomas S, Lepage M, Takagi N, Hirata H, Thibault-Starzyk F. Platinum Sintering on H-ZSM-5 Followed by Chemometrics of CO Adsorption and 2D Pressure-Jump IR Spectroscopy of Adsorbed Species. Angew Chem Int Ed Engl 2009; 49:785-9. [DOI: 10.1002/anie.200905181] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Rivallan M, Seguin E, Thomas S, Lepage M, Takagi N, Hirata H, Thibault-Starzyk F. Platinum Sintering on H-ZSM-5 Followed by Chemometrics of CO Adsorption and 2D Pressure-Jump IR Spectroscopy of Adsorbed Species. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200905181] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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23
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Hanawa H, Kunimatsu K, Uchida H, Watanabe M. In situ ATR-FTIR study of bulk CO oxidation on a polycrystalline Pt electrode. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2009.05.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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24
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Nakamura M, Hanioka Y, Ouchida W, Yamada M, Hoshi N. Estimation of Surface Structure and Carbon Monoxide Oxidation Site of Shape-Controlled Pt Nanoparticles. Chemphyschem 2009; 10:2719-24. [DOI: 10.1002/cphc.200900486] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Santana JA, Ishikawa Y. Density-functional theory study of interactions between water and carbon monoxide adsorbed on platinum under electrochemical conditions. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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26
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Kunimatsu K, Hanawa H, Uchida H, Watanabe M. Role of adsorbed species in methanol oxidation on Pt studied by ATR-FTIRAS combined with linear potential sweep voltammetry. J Electroanal Chem (Lausanne) 2009. [DOI: 10.1016/j.jelechem.2009.04.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Temperature dependence of co-adsorption of carbon monoxide and water on highly dispersed Pt/C and PtRu/C electrodes studied by in-situ ATR-FTIRAS. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.02.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Role of terrace/step edge sites in CO adsorption/oxidation on a polycrystalline Pt electrode studied by in situ ATR-FTIR method. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.03.046] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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29
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Kunimatsu K, Sato T, Uchida H, Watanabe M. Adsorption/oxidation of CO on highly dispersed Pt catalyst studied by combined electrochemical and ATR-FTIRAS methods: oxidation of CO adsorbed on carbon-supported Pt catalyst and unsupported Pt black. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:3590-3601. [PMID: 18288871 DOI: 10.1021/la702441x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
ATR-FTIRAS measurements combined with linear potential sweep voltammetry were conducted to investigate oxidation of CO adsorbed on a highly dispersed Pt catalyst supported on carbon black, Pt/C, and carbon-unsupported Pt black catalyst, Pt-B. Bands nu(CO) of atop- and bridge-bonded COs were resolved into those of COs adsorbed at terrace and step edge sites by curve-fitting analysis. At the high coverage near the saturation, a band around 1950-1960 cm(-1) assigned to asymmetric bridge-bonded CO, CO(B)(asym), was observed to develop on both Pt/C and Pt-B, which was the predominant type on the latter. Preferential oxidation of atop-CO adsorbed at the step edge site was commonly observed on both Pt/C and Pt-B during the potential sweep from 0.05 to 1.2 V. However, it has been found that CO(B)(asym) is the most reactive species. The high reactivity of the CO(B)(asym) on Pt/C and Pt-B is demonstrated for the first time in the present report. Adsorption of CO on the Pt/C and Pt-B resulted in growth of a sharp nu(OH) band around 3642-3645 cm(-1) which is assigned to non-hydrogen-bonded water molecules coadsorbed with CO. The nu(OH) band frequency exhibits a linear increase with potential with a Stark tuning rate of ca. 20 cm(-1)/V. Analysis of the potential dependence of this band in the CO oxidation potential region led us to conclude that this is the oxygen-containing species to oxidize adsorbed CO. Stark tuning rates of nu(CO) bands for the COs at the terrace and step edge sites on both Pt/C and Pt-B are almost independent of the adsorption sites for both atop- and bridge-bonded COs. However, CO(B)(asym) exhibits tuning rates of 41 cm-1/V and 37 cm-1/ V on Pt/C and Pt-B, respectively, which is in between the rates of atop and symmetric bridge-bonded COs.
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Affiliation(s)
- Keiji Kunimatsu
- Clean Energy Research Center and Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4 Takeda, Kofu 400-8510, Japan
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30
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Susut C, Chapman GB, Samjeské G, Osawa M, Tong Y. An unexpected enhancement in methanol electro-oxidation on an ensemble of Pt(111) nanofacets: a case of nanoscale single crystal ensemble electrocatalysis. Phys Chem Chem Phys 2008; 10:3712-21. [DOI: 10.1039/b802708k] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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