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Chien TE, Hohmann L, Harding DJ. Time-resolved surface reaction kinetics in the pressure gap. Faraday Discuss 2024. [PMID: 38757526 DOI: 10.1039/d3fd00158j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
We extend the use of our recently developed Near-Ambient Pressure Velocity Map Imaging (NAP-VMI) technique to study the kinetics and dynamics of catalytic reactions in the pressure gap. As an example, we show that NAP-VMI combined with molecular beam surface scattering allows the direct measurement of time- and velocity-resolved kinetics of the scattering and oxidation of CO on the Pd(110) surface with oxygen pressures at the surface up to 1 × 10-5 mbar, where different metastable surface structures form. Our results show that the c(2 × 4) oxide structure formed at low O2 pressure is highly active for CO oxidation. The velocity distribution of the CO2 products shows the presence of two reaction channels, which we attribute to reactions starting from two distinct but rapidly interconverting CO binding sites. The effective CO oxidation reaction activation energy is Er = (1.0 ± 0.13) eV. The CO2 production is suppressed at higher O2 pressure due to the number of antiphase domain boundaries increasing, and the missing row sites are filled by O-atoms at O2 pressures approaching 1 × 10-6 mbar. Filling of these sites by O-atoms reduces the CO surface lifetime, meaning the surface oxide is inactive for CO oxidation. We briefly outline further developments planned for the NAP-VMI and its application to other types of experiments.
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Affiliation(s)
- Tzu-En Chien
- Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden.
| | - Lea Hohmann
- Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden.
| | - Dan J Harding
- Department of Chemical Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden.
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2
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Degerman D, Goodwin CM, Lömker P, García-Martínez F, Shipilin M, Gloskovskii A, Nilsson A. Demonstrating Pressure Jumping as a Tool to Address the Pressure Gap in High Pressure Photoelectron Spectroscopy of CO and CO 2 Hydrogenation on Rh(211). Chemphyschem 2024; 25:e202300523. [PMID: 37877432 DOI: 10.1002/cphc.202300523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 10/26/2023]
Abstract
Operando probing by x-ray photoelectron spectroscopy (XPS) of certain hydrogenation reactions are often limited by the scattering of photoelectrons in the gas phase. This work describes a method designed to partially circumvent this so called pressure gap. By performing a rapid switch from a high pressure (where acquisition is impossible) to a lower pressure we can for a short while probe a "remnant" of the high pressure surface as well as the time dynamics during the re-equilibration to the new pressure. This methodology is demonstrated using the CO2 and the CO hydrogenation reaction over Rh(211). In the CO2 hydrogenation reaction, the remnant surface of a 2 bar pressure shows an adsorbate distribution which favors chemisorbed CHx adsorbates over chemisorbed CO. This contrasts against previous static operando spectra acquired at lower pressures. Furthermore, the pressure jumping method yields a faster acquisition and more detailed spectra than static operando measurements above 1 bar. In the CO hydrogenation reaction, we observe that CHx accumulated faster during the 275 mbar low pressure regime, and different hypotheses are presented regarding this observation.
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Affiliation(s)
- David Degerman
- Department of Physics, Stockholm University, AlbaNova University Center, Roslagstullsbacken 21, 114 21, Stockholm, Sweden
| | - Christopher M Goodwin
- Department of Physics, Stockholm University, AlbaNova University Center, Roslagstullsbacken 21, 114 21, Stockholm, Sweden
- Present Address: ALBA Synchrotron Light Facility, Carrer de la Llum 2, 26, 08290, Cerdanyola del Vallés, Spain
| | - Patrick Lömker
- Department of Physics, Stockholm University, AlbaNova University Center, Roslagstullsbacken 21, 114 21, Stockholm, Sweden
| | | | - Mikhail Shipilin
- Department of Physics, Stockholm University, AlbaNova University Center, Roslagstullsbacken 21, 114 21, Stockholm, Sweden
| | - Andrei Gloskovskii
- Deutsches Elektronen Synchrotron DESY, Notkestraße 85, 226 07, Hamburg, Germany
| | - Anders Nilsson
- Department of Physics, Stockholm University, AlbaNova University Center, Roslagstullsbacken 21, 114 21, Stockholm, Sweden
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3
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Roger M, Artiglia L, Boucly A, Buttignol F, Agote-Arán M, van Bokhoven JA, Kröcher O, Ferri D. Improving time-resolution and sensitivity of in situ X-ray photoelectron spectroscopy of a powder catalyst by modulated excitation. Chem Sci 2023; 14:7482-7491. [PMID: 37449079 PMCID: PMC10337771 DOI: 10.1039/d3sc01274c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023] Open
Abstract
Ambient pressure X-ray photoelectron spectroscopy (APXPS) is a powerful tool to characterize the surface structure of heterogeneous catalysts in situ. In order to improve the time resolution and the signal-to-noise (S/N) ratio of photoemission spectra, we collected consecutive APXP spectra during the periodic perturbation of a powder Pd/Al2O3 catalyst away from its equilibrium state according to the modulated excitation approach (ME). Averaging of the spectra along the alternate pulses of O2 and CO improved the S/N ratio demonstrating that the time resolution of the measurement can be limited solely to the acquisition time of one spectrum. Through phase sensitive analysis of the averaged time-resolved spectra, the formation/consumption dynamics of three oxidic species, two metal species, adsorbed CO on Pd0 as well as Pdn+ (n > 2) was followed along the gas switches. Pdn+ and 2-fold surface PdO species were recognised as most reactive to the gas switches. Our approach demonstrates that phase sensitive detection of time-resolved XPS data allows following the dynamics of reactive species at the solid-gas interface under different reaction environments with unprecedented precision.
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Affiliation(s)
- M Roger
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
- École Polytechnique Fédérale de Lausanne (EPFL), Institute for Chemical Sciences and Engineering CH-1015 Lausanne Switzerland
| | - L Artiglia
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
| | - A Boucly
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
| | - F Buttignol
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
- École Polytechnique Fédérale de Lausanne (EPFL), Institute for Chemical Sciences and Engineering CH-1015 Lausanne Switzerland
| | - M Agote-Arán
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
| | - J A van Bokhoven
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
- Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zurich 8093 Zurich Switzerland
| | - O Kröcher
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
- École Polytechnique Fédérale de Lausanne (EPFL), Institute for Chemical Sciences and Engineering CH-1015 Lausanne Switzerland
| | - D Ferri
- Paul Scherrer Institut Forschungsstrasse 111, CH-5232 Villigen PSI Switzerland
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van den Boorn BFH, van Berkel M, Bieberle‐Hütter A. Variance‐Based Global Sensitivity Analysis: A Methodological Framework and Case Study for Microkinetic Modeling. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Bart F. H. van den Boorn
- Electrochemical Materials and Interfaces DIFFER ‐ Dutch Institute for Fundamental Energy Research De Zaale 20 Eindhoven 5612 AJ The Netherlands
| | - Matthijs van Berkel
- Energy Systems and Control DIFFER ‐ Dutch Institute for Fundamental Energy Research De Zaale 20 Eindhoven 5612 AJ The Netherlands
| | - Anja Bieberle‐Hütter
- Electrochemical Materials and Interfaces DIFFER ‐ Dutch Institute for Fundamental Energy Research De Zaale 20 Eindhoven 5612 AJ The Netherlands
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Lian X, Gao J, Ding Y, Liu Y, Chen W. Unraveling Catalytic Reaction Mechanism by In Situ Near Ambient Pressure X-ray Photoelectron Spectroscopy. J Phys Chem Lett 2022; 13:8264-8277. [PMID: 36036437 DOI: 10.1021/acs.jpclett.2c01191] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Probing surface chemistry during reactions closer to realistic conditions is crucial for the understanding of mechanisms in heterogeneous catalysis. Near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) is one of the state-of-the-art surface-sensitive techniques used to characterize catalyst surfaces in gas phases. This Perspective begins with a brief overview of the development of the NAP-XPS technique and its representative applications in identifying the active sites at a molecular level. Next, recent in situ NAP-XPS investigations of several model catalysts in the CO2 hydrogenation reaction are mainly discussed. Finally, we highlight the major challenges facing NAP-XPS and future improvements to facilities for probing intermediates with higher resolutions under real ambient pressure reactions in heterogeneous catalysis.
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Affiliation(s)
- Xu Lian
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Jiajia Gao
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Yishui Ding
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, PR China
| | - Yuan Liu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, PR China
| | - Wei Chen
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, PR China
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
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Nilsson A. Concluding remarks: Photoelectron spectroscopy and the future of surface analysis. Faraday Discuss 2022; 236:528-544. [PMID: 35838079 DOI: 10.1039/d2fd90028a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Faraday Discussion on Photoelectron Spectroscopy and the Future of Surface Analysis was held both in person and virtually in London, April 20-22, 2022. In my concluding lecture I have highlighted three different recent directions in the field; (i) in situ and operando, (ii) buried interfaces and (iii) time resolved measurements. I have based my lecture on most recent studies conducted in my research group in all these 3 directions. In particular, the new operando instrument POLARIS, located at the brightest hard X-ray beamline at DESY for photoelectron spectroscopy, has opened new avenues to address important problems in catalysis that are essential for society to become fossil free.
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Affiliation(s)
- Anders Nilsson
- Department of Physics, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden.
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Poths P, Alexandrova AN. Theoretical Perspective on Operando Spectroscopy of Fluxional Nanocatalysts. J Phys Chem Lett 2022; 13:4321-4334. [PMID: 35536346 DOI: 10.1021/acs.jpclett.2c00628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Improvements in operando spectroscopy have enabled the catalysis community to investigate the dynamic nature of catalysts under operating conditions with increasing detail. Still, the highly dynamic nature of some catalysts, such as fluxional supported subnano clusters, presents a formidable challenge even for the most state-of-the-art techniques. The reason is that such fluxional catalytic interfaces contain a variety of thermally accessible states. Operando spectroscopies used in catalysis generally fall into two categories: ensemble-based techniques, which provide spectra containing the signals of the entire ensemble of states of the catalyst and are not necessarily dominated by the most active species, and localized techniques, which provide atomistic-level information about the dynamics of active sites in a very small area, which might not include the most active species. Combining many different kinds of techniques can provide detailed insight; however, we propose that effective utilization of specific computational techniques and approaches within the fluxionality paradigm can fill the gap and enable atomistic characterization of the most relevant catalytic sites.
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Affiliation(s)
- Patricia Poths
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Anastassia N Alexandrova
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
- California NanoSystems Institute, Los Angeles, California 90095, United States
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Pérez-Dieste V. Characterization of model and real catalysts by APXPS. EPJ WEB OF CONFERENCES 2022. [DOI: 10.1051/epjconf/202227301005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In this contribution, I first briefly summarize some of the recent advances relevant for the investigation of heterogeneous catalysis with Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS). In the second part, two examples of the research done at the CIRCE beamline of the synchrotron ALBA are described: CO oxidation on a model curved crystal Pd(111) catalyst and methanol steam reforming on powder bimetallic supported catalysts, PdCu/ monoclinic and cubic zirconia.
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Flavell W. Spiers Memorial Lecture: Prospects for photoelectron spectroscopy. Faraday Discuss 2022; 236:9-57. [DOI: 10.1039/d2fd00071g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An overview is presented of recent advances in photoelectron spectroscopy, focussing on advances in in situ and time-resolved measurements, and in extending the sampling depth of the technique. The future...
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