1
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Makogon A, Noël JM, Kanoufi F, Shkirskiy V. Deciphering the Interplay between Local and Global Dynamics of Anodic Metal Oxidation. Anal Chem 2024; 96:1129-1137. [PMID: 38197168 DOI: 10.1021/acs.analchem.3c04160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
The stark difference between global and local metal oxidation dynamics underscores the need for methodologies capable of performing precise sub-μm-scale and wide-field measurements. In this study, we present reflective microscopy as a tool developed to address this challenge, illustrated by the example of chronoamperometric Fe oxidation in a NaCl solution. Analysis at a local scale of 10 s of μm has revealed three distinct periods of Fe oxidation: the initial covering of the metal interface with a surface film, followed by the electrochemical conversion of the formed surface film, and finally, the in-depth oxidation of Fe. In addition, thermodynamic calculations and the quantitative analysis of changes in optical signal (light intensity), correlated with variations in refractive indexes, suggest the initial formation of maghemite, followed by its subsequent conversion to magnetite. The reactivity maps for all three periods are heterogeneous, which can be attributed to the preferential oxidation of certain crystallographic grains. Notably, at the global scale of 100 s of μm, reactivity initiates at the electrode border and progresses toward its center, demonstrating a unique pattern that is independent of the local metal structure. This finding underscores the significance of simultaneously employing sub-μm-precise, quantitative, and wide-field measurements for a comprehensive description of metal oxidation processes.
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Affiliation(s)
| | - Jean-Marc Noël
- ITODYS, CNRS, Université Paris Cité, 75013 Paris, France
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2
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Pfaff S, Larsson A, Orlov D, Rämisch L, Gericke SM, Lundgren E, Zetterberg J. A Polycrystalline Pd Surface Studied by Two-Dimensional Surface Optical Reflectance during CO Oxidation: Bridging the Materials Gap. ACS APPLIED MATERIALS & INTERFACES 2024; 16:444-453. [PMID: 38109219 PMCID: PMC10788831 DOI: 10.1021/acsami.3c11341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/19/2023] [Accepted: 11/13/2023] [Indexed: 12/20/2023]
Abstract
Industrial catalysts are complex materials systems operating in harsh environments. The active parts of the catalysts are nanoparticles that expose different facets with different surface orientations at which the catalytic reactions occur. However, these facets are close to impossible to study in detail under industrially relevant operating conditions. Instead, simpler model systems, such as single crystals with a well-defined surface orientation, have been successfully used to study gas-surface interactions such as adsorption and desorption, surface oxidation, and oxidation/reduction reactions. To more closely mimic the many facets exhibited by nanoparticles and thereby close the so-called materials gap, there has also been a recent move toward using polycrystalline surfaces and curved crystals. However, these studies are limited either by the pressure or spatial resolution at realistic pressures or by the number of surfaces studied simultaneously. In this work, we demonstrate the use of reflectance microscopy to study a vast number of catalytically active surfaces simultaneously under realistic and identical reaction conditions. As a proof of concept, we have conducted an operando experiment to study CO oxidation over a Pd polycrystal, where the polycrystalline surface acts as a collection of many single-crystal surfaces. Finally, we visualized the resulting data by plotting the reflectivity as a function of surface orientation. We think the techniques and visualization methods introduced in this work will be key toward bridging the materials gap in catalysis.
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Affiliation(s)
- Sebastian Pfaff
- Combustion
Research Facility, Sandia National Laboratories, 7011 East Ave, Livermore, California 94550, United States
| | - Alfred Larsson
- Division
of Synchrotron Radiation Research, Lund
University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Dmytro Orlov
- Division
of Mechanics, Materials and Component Design, Lund University, Ole
Römers väg 1, S-22363 Lund, Sweden
| | - Lisa Rämisch
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Sabrina M. Gericke
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Edvin Lundgren
- Division
of Synchrotron Radiation Research, Lund
University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Johan Zetterberg
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
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3
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Pfaff S, Rämisch L, Gericke SM, Larsson A, Lundgren E, Zetterberg J. Visualizing the Gas Diffusion Induced Ignition of a Catalytic Reaction. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sebastian Pfaff
- Lund University, Combustion Physics, Sölvegatan 14, S-22363 Lund, Sweden
| | - Lisa Rämisch
- Lund University, Combustion Physics, Sölvegatan 14, S-22363 Lund, Sweden
| | - Sabrina M. Gericke
- Lund University, Combustion Physics, Sölvegatan 14, S-22363 Lund, Sweden
| | - Alfred Larsson
- Lund University, Division of Synchrotron Radiation Research, Sölvegatan 14, S-22363 Lund, Sweden
| | - Edvin Lundgren
- Lund University, Division of Synchrotron Radiation Research, Sölvegatan 14, S-22363 Lund, Sweden
| | - Johan Zetterberg
- Lund University, Combustion Physics, Sölvegatan 14, S-22363 Lund, Sweden
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4
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Pfaff S, Larsson A, Orlov D, Harlow GS, Abbondanza G, Linpé W, Rämisch L, Gericke SM, Zetterberg J, Lundgren E. Operando Reflectance Microscopy on Polycrystalline Surfaces in Thermal Catalysis, Electrocatalysis, and Corrosion. ACS APPLIED MATERIALS & INTERFACES 2021; 13:19530-19540. [PMID: 33870682 PMCID: PMC8288973 DOI: 10.1021/acsami.1c04961] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/05/2021] [Indexed: 06/12/2023]
Abstract
We have developed a microscope with a spatial resolution of 5 μm, which can be used to image the two-dimensional surface optical reflectance (2D-SOR) of polycrystalline samples in operando conditions. Within the field of surface science, operando tools that give information about the surface structure or chemistry of a sample under realistic experimental conditions have proven to be very valuable to understand the intrinsic reaction mechanisms in thermal catalysis, electrocatalysis, and corrosion science. To study heterogeneous surfaces in situ, the experimental technique must both have spatial resolution and be able to probe through gas or electrolyte. Traditional electron-based surface science techniques are difficult to use under high gas pressure conditions or in an electrolyte due to the short mean free path of electrons. Since it uses visible light, SOR can easily be used under high gas pressure conditions and in the presence of an electrolyte. In this work, we use SOR in combination with a light microscope to gain information about the surface under realistic experimental conditions. We demonstrate this by studying the different grains of three polycrystalline samples: Pd during CO oxidation, Au in electrocatalysis, and duplex stainless steel in corrosion. Optical light-based techniques such as SOR could prove to be a good alternative or addition to more complicated techniques in improving our understanding of complex polycrystalline surfaces with operando measurements.
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Affiliation(s)
- Sebastian Pfaff
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Alfred Larsson
- Division
of Synchrotron Radiation Research, Lund
University, Sölvegatan
14, S-22363 Lund, Sweden
| | - Dmytro Orlov
- Materials
Engineering, Lund University, Ole Römers väg 1, S-22363 Lund, Sweden
| | - Gary S. Harlow
- Department
of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Giuseppe Abbondanza
- Division
of Synchrotron Radiation Research, Lund
University, Sölvegatan
14, S-22363 Lund, Sweden
| | - Weronica Linpé
- Division
of Synchrotron Radiation Research, Lund
University, Sölvegatan
14, S-22363 Lund, Sweden
| | - Lisa Rämisch
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Sabrina M. Gericke
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Johan Zetterberg
- Combustion
Physics, Lund University, Sölvegatan 14, S-22363 Lund, Sweden
| | - Edvin Lundgren
- Division
of Synchrotron Radiation Research, Lund
University, Sölvegatan
14, S-22363 Lund, Sweden
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5
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Hejral U, Shipilin M, Gustafson J, Stierle A, Lundgren E. High energy surface x-ray diffraction applied to model catalyst surfaces at work. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:073001. [PMID: 33690191 DOI: 10.1088/1361-648x/abb17c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Catalysts are materials that accelerate the rate of a desired chemical reaction. As such, they constitute an integral part in many applications ranging from the production of fine chemicals in chemical industry to exhaust gas treatment in vehicles. Accordingly, it is of utmost economic interest to improve catalyst efficiency and performance, which requires an understanding of the interplay between the catalyst structure, the gas phase and the catalytic activity under realistic reaction conditions at ambient pressures and elevated temperatures. In recent years efforts have been made to increasingly develop techniques that allow for investigating model catalyst samples under conditions closer to those of real technical catalysts. One of these techniques is high energy surface x-ray diffraction (HESXRD), which uses x-rays with photon energies typically in the range of 70-80 keV. HESXRD allows a fast data collection of three dimensional reciprocal space for the structure determination of model catalyst samples under operando conditions and has since been used for the investigation of an increasing number of different model catalysts. In this article we will review general considerations of HESXRD including its working principle for different model catalyst samples and the experimental equipment required. An overview over HESXRD investigations performed in recent years will be given, and the advantages of HESXRD with respect to its application to different model catalyst samples will be presented. Moreover, the combination of HESXRD with other operando techniques such as in situ mass spectrometry, planar laser-induced fluorescence and surface optical reflectance will be discussed. The article will close with an outlook on future perspectives and applications of HESXRD.
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Affiliation(s)
- Uta Hejral
- Division of Synchrotron Radiation Research, Lund University, 221 00 Lund, Sweden
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
- Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany
| | - Mikhail Shipilin
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
| | - Johan Gustafson
- Division of Synchrotron Radiation Research, Lund University, 221 00 Lund, Sweden
| | - Andreas Stierle
- Deutsches Elektronen-Synchrotron DESY, 22603 Hamburg, Germany
- Fachbereich Physik, Universität Hamburg, 20355 Hamburg, Germany
| | - Edvin Lundgren
- Division of Synchrotron Radiation Research, Lund University, 221 00 Lund, Sweden
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6
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Zong C, Zhang C, Lin P, Yin J, Bai Y, Lin H, Ren B, Cheng JX. Real-time imaging of surface chemical reactions by electrochemical photothermal reflectance microscopy. Chem Sci 2020; 12:1930-1936. [PMID: 34163957 PMCID: PMC8179047 DOI: 10.1039/d0sc05132b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Traditional electrochemical measurements based on either current or potential responses only present the average contribution of an entire electrode's surface. Here, we present an electrochemical photothermal reflectance microscope (EPRM) in which a potential-dependent nonlinear photothermal signal is exploited to map an electrochemical process with sub-micron spatial resolution. By using EPRM, we are able to monitor the photothermal signal of a Pt electrode during the electrochemical reaction at an imaging speed of 0.3 s per frame. The potential-dependent photothermal signal, which is sensitive to the free electron density, clearly revealed the evolution of surface species on the Pt surface. Our results agreed well with the reported spectroelectrochemical techniques under similar conditions but with a much faster imaging speed. We further mapped the potential oscillation during the oxidation of formic acid on the Pt surface. The photothermal images from the Pt electrode well matched the potential change. This technique opens new prospects for real-time imaging of surface chemical reaction to reveal the heterogeneity of electrochemical reactivity, which enables broad applications to the study of catalysis, energy storage, and light harvest systems. The potential-dependent photothermal signal, which is sensitive to the free electron density, map the evolution of surface species on the electrode in real time. ![]()
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Affiliation(s)
- Cheng Zong
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA .,State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Chi Zhang
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA
| | - Peng Lin
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA
| | - Jiaze Yin
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA
| | - Yeran Bai
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA
| | - Haonan Lin
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA
| | - Bin Ren
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
| | - Ji-Xin Cheng
- Department of Biomedical Engineering, Department of Electrical & Computer Engineering, Department of Chemistry, Department of Physics, Photonics Center, Boston University Boston MA 02215 USA
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7
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Linpé W, Harlow GS, Larsson A, Abbondanza G, Rämisch L, Pfaff S, Zetterberg J, Evertsson J, Lundgren E. An electrochemical cell for 2-dimensional surface optical reflectance during anodization and cyclic voltammetry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:044101. [PMID: 32357721 DOI: 10.1063/1.5133905] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
We have developed an electrochemical cell for in situ 2-Dimensional Surface Optical Reflectance (2D-SOR) studies during anodization and cyclic voltammetry. The 2D-SOR signal was recorded from electrodes made of polycrystalline Al, Au(111), and Pt(100) single crystals. The changes can be followed at a video rate acquisition frequency of 200 Hz and demonstrate a strong contrast between oxidizing and reducing conditions. Good correlation between the 2D-SOR signal and the anodization conditions or the cyclic voltammetry current is also observed. The power of this approach is discussed, with a focus on applications in various fields of electrochemistry. The combination of 2D-SOR with other techniques, as well as its spatial resolution and sensitivity, has also been discussed.
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Affiliation(s)
- W Linpé
- Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden
| | - G S Harlow
- Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden
| | - A Larsson
- Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden
| | - G Abbondanza
- Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden
| | - L Rämisch
- Division of Combustion Physics, Lund University, SE-22100 Lund, Sweden
| | - S Pfaff
- Division of Combustion Physics, Lund University, SE-22100 Lund, Sweden
| | - J Zetterberg
- Division of Combustion Physics, Lund University, SE-22100 Lund, Sweden
| | - J Evertsson
- Hydro Extruded Solutions AB Innovation & Technology, Finspång, Sweden
| | - E Lundgren
- Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden
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8
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Photoreduction of a Pd-Doped Mesoporous TiO2 Photocatalyst for Hydrogen Production under Visible Light. Catalysts 2020. [DOI: 10.3390/catal10010074] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Photoreduction with visible light can enhance the photocatalytic activity of TiO2 for the production of hydrogen. In this article, we present a strategy to photoreduce a palladium-doped TiO2 photocatalyst by using near-UV light prior to its utilization. A sol-gel methodology was employed to prepare the photocatalysts with different metal loadings (0.25–5.00 wt% Pd). The structural and morphological characteristics of the synthesized Pd-TiO2 were analyzed by using X-ray Diffraction (XRD), BET Surface Area (SBET), TemperatureProgrammed Reduction (TPR), Chemisorption and X-ray Photoelectron Spectroscopy (XPS). Hydrogen was produced by water splitting under visible light irradiation using ethanol as an organic scavenger. Experiments were developed in the Photo-CREC Water-II (PCW-II) Reactor designed at the CREC-UWO (Chemical Reactor Engineering Centre). It was shown that the mesoporous 0.25 wt% Pd-TiO2 with 2.5 1eV band gap exhibits, under visible light, the best hydrogen production performance, with a 1.58% Quantum Yield being achieved.
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9
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Escobedo S, Rusinque B, de Lasa H. Photochemical Thermodynamic Efficiency Factors (PTEFs) for Hydrogen Production Using Different TiO2 Photocatalysts. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Salvador Escobedo
- Faculty of Engineering, Chemical Reactor Engineering Centre (CREC), Western University, London, Ontario N6A 5B9, Canada
| | - Bianca Rusinque
- Faculty of Engineering, Chemical Reactor Engineering Centre (CREC), Western University, London, Ontario N6A 5B9, Canada
| | - Hugo de Lasa
- Faculty of Engineering, Chemical Reactor Engineering Centre (CREC), Western University, London, Ontario N6A 5B9, Canada
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10
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Combining Planar Laser-Induced Fluorescence with Stagnation Point Flows for Small Single-Crystal Model Catalysts: CO Oxidation on a Pd(100). Catalysts 2019. [DOI: 10.3390/catal9050484] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A stagnation flow reactor has been designed and characterized for both experimental and modeling studies of single-crystal model catalysts in heterogeneous catalysis. Using CO oxidation over a Pd(100) single crystal as a showcase, we have employed planar laser-induced fluorescence (PLIF) to visualize the CO2 distribution over the catalyst under reaction conditions and subsequently used the 2D spatially resolved gas phase data to characterize the stagnation flow reactor. From a comparison of the experimental data and the stagnation flow model, it was found that characteristic stagnation flow can be achieved with the reactor. Furthermore, the combined stagnation flow/PLIF/modeling approach makes it possible to estimate the turnover frequency (TOF) of the catalytic surface from the measured CO2 concentration profiles above the surface and to predict the CO2, CO and O2 concentrations at the surface under reaction conditions.
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11
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Pfaff S, Zhou J, Hejral U, Gustafson J, Shipilin M, Albertin S, Blomberg S, Gutowski O, Dippel A, Lundgren E, Zetterberg J. Combining high-energy X-ray diffraction with Surface Optical Reflectance and Planar Laser Induced Fluorescence for operando catalyst surface characterization. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:033703. [PMID: 30927778 DOI: 10.1063/1.5086925] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 02/17/2019] [Indexed: 06/09/2023]
Abstract
We have combined three techniques, High Energy Surface X-Ray Diffraction (HESXRD), Surface Optical Reflectance, and Planar Laser Induced Fluorescence in an operando study of CO oxidation over a Pd(100) catalyst. We show that these techniques provide useful new insights such as the ability to verify that the finite region being probed by techniques such as HESXRD is representative of the sample surface as a whole. The combination is also suitable to determine when changes in gas composition or surface structure and/or morphology occur and to subsequently correlate them with high temporal resolution. In the study, we confirm previous results which show that the Pd(100) surface reaches high activity before an oxide can be detected. Furthermore, we show that the single crystal catalyst surface does not behave homogeneously, which we attribute to the surface being exposed to inhomogeneous gas conditions in mass transfer limited scenarios.
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Affiliation(s)
- S Pfaff
- Combustion Physics, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - J Zhou
- Combustion Physics, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - U Hejral
- Synchrotron Radiation Research, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - J Gustafson
- Synchrotron Radiation Research, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - M Shipilin
- Department of Physics, AlbaNova University Center, Stockholm University, 10691 Stockholm, Sweden
| | - S Albertin
- Synchrotron Radiation Research, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - S Blomberg
- Synchrotron Radiation Research, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - O Gutowski
- Photon Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
| | - A Dippel
- Photon Science, DESY, Notkestrasse 85, Hamburg 22607, Germany
| | - E Lundgren
- Synchrotron Radiation Research, Lund University, P.O. Box 118, Lund 22100, Sweden
| | - J Zetterberg
- Combustion Physics, Lund University, P.O. Box 118, Lund 22100, Sweden
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