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Usoltsev O, Tereshchenko A, Skorynina A, Kozyr E, Soldatov A, Safonova O, Clark AH, Ferri D, Nachtegaal M, Bugaev A. Machine Learning for Quantitative Structural Information from Infrared Spectra: The Case of Palladium Hydride. SMALL METHODS 2024; 8:e2301397. [PMID: 38295064 DOI: 10.1002/smtd.202301397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 01/09/2024] [Indexed: 02/02/2024]
Abstract
Infrared spectroscopy (IR) is a widely used technique enabling to identify specific functional groups in the molecule of interest based on their characteristic vibrational modes or the presence of a specific adsorption site based on the characteristic vibrational mode of an adsorbed probe molecule. The interpretation of an IR spectrum is generally carried out within a fingerprint paradigm by comparing the observed spectral features with the features of known references or theoretical calculations. This work demonstrates a method for extracting quantitative structural information beyond this approach by application of machine learning (ML) algorithms. Taking palladium hydride formation as an example, Pd-H pressure-composition isotherms are reconstructed using IR data collected in situ in diffuse reflectance using CO molecule as a probe. To the best of the knowledge, this is the first example of the determination of continuous structural descriptors (such as interatomic distance and stoichiometric coefficient) from the fine structure of vibrational spectra, which opens new possibilities of using IR spectra for structural analysis.
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Affiliation(s)
- Oleg Usoltsev
- ALBA Synchrotron, Cerdanyola del Valles, Barcelona, 08290, Spain
| | | | - Alina Skorynina
- ALBA Synchrotron, Cerdanyola del Valles, Barcelona, 08290, Spain
| | | | - Alexander Soldatov
- Southern Federal University, Sladkova 178/24, Rostov-on-Don, 344090, Russia
| | - Olga Safonova
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen, 5232, Switzerland
| | - Adam H Clark
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen, 5232, Switzerland
| | - Davide Ferri
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen, 5232, Switzerland
| | - Maarten Nachtegaal
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen, 5232, Switzerland
| | - Aram Bugaev
- Paul Scherrer Institute, Forschungsstrasse 111, Villigen, 5232, Switzerland
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Usoltsev O, Stoian D, Skorynina A, Kozyr E, Njoroge PN, Pellegrini R, Groppo E, van Bokhoven JA, Bugaev A. Restructuring of Palladium Nanoparticles during Oxidation by Molecular Oxygen. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2401184. [PMID: 38884188 DOI: 10.1002/smll.202401184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 06/02/2024] [Indexed: 06/18/2024]
Abstract
An interplay between Pd and PdO and their spatial distribution inside the particles are relevant for numerous catalytic reactions. Using in situ time-resolved X-ray absorption spectroscopy (XAS) supported by theoretical simulations, a mechanistic picture of the structural evolution of 2.3 nm palladium nanoparticles upon their exposure to molecular oxygen is provided. XAS analysis revealed the restructuring of the fcc-like palladium surface into the 4-coordinated structure of palladium oxide upon absorption of oxygen from the gas phase and formation of core@shell Pd@PdO structures. The reconstruction starts from the low-coordinated sites at the edges of palladium nanoparticles. Formation of the PdO shell does not affect the average Pd‒Pd coordination numbers, since the decrease of the size of the metallic core is compensated by a more spherical shape of the oxidized nanoparticles due to a weaker interaction with the support. The metallic core is preserved below 200 °C even after continuous exposure to oxygen, with its size decreasing insignificantly upon increasing the temperature, while above 200 °C, bulk oxidation proceeds. The Pd‒Pd distances in the metallic phase progressively decrease upon increasing the fraction of the Pd oxide due to the alignment of the cell parameters of the two phases.
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Affiliation(s)
- Oleg Usoltsev
- ALBA Synchrotron, Cerdanyola del Valles, Barcelona, 08290, Spain
| | - Dragos Stoian
- The Swiss-Norwegian Beamlines (SNBL) at ESRF, BP 220, Grenoble, 38043, France
| | - Alina Skorynina
- ALBA Synchrotron, Cerdanyola del Valles, Barcelona, 08290, Spain
| | - Elizaveta Kozyr
- Department of Chemistry, INSTM and NIS Centre, University of Torino, via Quarello 15A, Turin, 10125, Italy
| | - Peter N Njoroge
- Department of Chemistry, University of Oslo, Sem Saelandsvei 26, Oslo, 0315, Norway
| | - Riccardo Pellegrini
- Chimet S.p.A. - Catalyst Division, Via di Pescaiola 74, Viciomaggio Arezzo, 52041, Italy
| | - Elena Groppo
- Department of Chemistry, INSTM and NIS Centre, University of Torino, via Quarello 15A, Turin, 10125, Italy
| | - Jeroen A van Bokhoven
- Paul Scherrer Institute, Villigen, 5232, Switzerland
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1, Zurich, 8093, Switzerland
| | - Aram Bugaev
- Paul Scherrer Institute, Villigen, 5232, Switzerland
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Bugaev AL, Usoltsev OA, Guda AA, Lomachenko KA, Brunelli M, Groppo E, Pellegrini R, Soldatov AV, van Bokhoven JA. Hydrogenation of ethylene over palladium: evolution of the catalyst structure by operando synchrotron-based techniques. Faraday Discuss 2021; 229:197-207. [PMID: 33656030 DOI: 10.1039/c9fd00139e] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Palladium-based catalysts are exploited on an industrial scale for the selective hydrogenation of hydrocarbons. The formation of palladium carbide and hydride phases under reaction conditions changes the catalytic properties of the material, which points to the importance of operando characterization for determining the relation between the relative fractions of the two phases and the catalyst performance. We present a combined time-resolved characterization by X-ray absorption spectroscopy (in both near-edge and extended regions) and X-ray diffraction of a working palladium-based catalyst during the hydrogenation of ethylene in a wide range of partial pressures of ethylene and hydrogen. Synergistic coupling of multiple techniques allowed us to follow the structural evolution of the palladium lattice as well as the transitions between the metallic, hydride and carbide phases of palladium. The nanometric dimensions of the particles resulted in the considerable contribution of both surface and bulk carbides to the X-ray absorption spectra. During the reaction, palladium carbide is formed, which does not lead to a loss of activity. Unusual contraction of the unit cell parameter of the palladium lattice in the spent catalyst was observed upon increasing hydrogen partial pressure.
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Affiliation(s)
- Aram L Bugaev
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, 344090, Russia.
| | - Oleg A Usoltsev
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, 344090, Russia.
| | - Alexander A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, 344090, Russia.
| | - Kirill A Lomachenko
- BM23/ID24, European Synchrotron Radiation Facility, 71 avenue des Martyrs, 38043 Grenoble Cedex 9, France
| | - Michela Brunelli
- DUBBLE CRG at the European Synchrotron Radiation Facility, Netherlands Organization for Scientific Research (NWO), 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Elena Groppo
- Department of Chemistry, NIS Interdepartmental Centre, University of Turin, via P. Giuria 7, 10125 Turin, Italy
| | - Riccardo Pellegrini
- Chimet S.p.A. - Catalyst Division, Via di Pescaiola 74, 52041 Viciomaggio Arezzo, Italy
| | - Alexander V Soldatov
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, 344090, Russia.
| | - Jeroen A van Bokhoven
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland and Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
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Madkhali MMM, Rankine CD, Penfold TJ. Enhancing the analysis of disorder in X-ray absorption spectra: application of deep neural networks to T-jump-X-ray probe experiments. Phys Chem Chem Phys 2021; 23:9259-9269. [PMID: 33885072 DOI: 10.1039/d0cp06244h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many chemical and biological reactions, including ligand exchange processes, require thermal energy for the reactants to overcome a transition barrier and reach the product state. Temperature-jump (T-jump) spectroscopy uses a near-infrared (NIR) pulse to rapidly heat a sample, offering an approach for triggering these processes and directly accessing thermally-activated pathways. However, thermal activation inherently increases the disorder of the system under study and, as a consequence, can make quantitative interpretations of structural changes challenging. In this Article, we optimise a deep neural network (DNN) for the instantaneous prediction of Co K-edge X-ray absorption near-edge structure (XANES) spectra. We apply our DNN to analyse T-jump pump/X-ray probe data pertaining to the ligand exchange processes and solvation dynamics of Co2+ in chlorinated aqueous solution. Our analysis is greatly facilitated by machine learning, as our DNN is able to predict quickly and cost-effectively the XANES spectra of thousands of geometric configurations sampled from ab initio molecular dynamics (MD) using nothing more than the local geometric environment around the X-ray absorption site. We identify directly the structural changes following the T-jump, which are dominated by sample heating and a commensurate increase in the Debye-Waller factor.
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Affiliation(s)
- Marwah M M Madkhali
- Chemistry - School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
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Rankine CD, Penfold TJ. Progress in the Theory of X-ray Spectroscopy: From Quantum Chemistry to Machine Learning and Ultrafast Dynamics. J Phys Chem A 2021; 125:4276-4293. [DOI: 10.1021/acs.jpca.0c11267] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- C. D. Rankine
- Chemistry—School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K
| | - T. J. Penfold
- Chemistry—School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K
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Usoltsev OA, Pnevskaya AY, Kamyshova EG, Tereshchenko AA, Skorynina AA, Zhang W, Yao T, Bugaev AL, Soldatov AV. Dehydrogenation of Ethylene on Supported Palladium Nanoparticles: A Double View from Metal and Hydrocarbon Sides. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1643. [PMID: 32825750 PMCID: PMC7560039 DOI: 10.3390/nano10091643] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/10/2020] [Accepted: 08/18/2020] [Indexed: 02/03/2023]
Abstract
Adsorption of ethylene on palladium, a key step in various catalytic reactions, may result in a variety of surface-adsorbed species and formation of palladium carbides, especially under industrially relevant pressures and temperatures. Therefore, the application of both surface and bulk sensitive techniques under reaction conditions is important for a comprehensive understanding of ethylene interaction with Pd-catalyst. In this work, we apply in situ X-ray absorption spectroscopy, X-ray diffraction and infrared spectroscopy to follow the evolution of the bulk and surface structure of an industrial catalysts consisting of 2.6 nm supported palladium nanoparticles upon exposure to ethylene under atmospheric pressure at 50 °C. Experimental results were complemented by ab initio simulations of atomic structure, X-ray absorption spectra and vibrational spectra. The adsorbed ethylene was shown to dehydrogenate to C2H3, C2H2 and C2H species, and to finally decompose to palladium carbide. Thus, this study reveals the evolution pathway of ethylene on industrial Pd-catalyst under atmospheric pressure at moderate temperatures, and provides a conceptual framework for the experimental and theoretical investigation of palladium-based systems, in which both surface and bulk structures exhibit a dynamic nature under reaction conditions.
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Affiliation(s)
- Oleg A. Usoltsev
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
| | - Anna Yu. Pnevskaya
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
| | - Elizaveta G. Kamyshova
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
| | - Andrei A. Tereshchenko
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
| | - Alina A. Skorynina
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
| | - Wei Zhang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China; (W.Z.); (T.Y.)
| | - Tao Yao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China; (W.Z.); (T.Y.)
| | - Aram L. Bugaev
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
| | - Alexander V. Soldatov
- The Smart Materials Research Institute, Southern Federal University, 178/24 Sladkova, 344090 Rostov-on-Don, Russia; (O.A.U.); (A.Y.P.); (E.G.K.); (A.A.T.); (A.A.S.); (A.V.S.)
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In Situ Time-Resolved Decomposition of β-Hydride Phase in Palladium Nanoparticles Coated with Metal-Organic Framework. METALS 2020. [DOI: 10.3390/met10060810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The formation of palladium hydrides is a well-known phenomenon, observed for both bulk and nanosized samples. The kinetics of hydrogen adsorption/desorption strongly depends on the particle size and shape, as well as the type of support and/or coating of the particles. In addition, the structural properties of hydride phases and their distribution also depend on the particle size. In this work, we report on the in situ characterization of palladium nanocubes coated with HKUST-1 metal-organic framework (Pd@HKUST-1) during desorption of hydrogen by means of synchrotron-based time-resolved X-ray powder diffraction. A slower hydrogen desorption, compared to smaller sized Pd nanoparticles was observed. Rietveld refinement of the time-resolved data revealed the remarkable stability of the lattice parameters of α- and β-hydride phases of palladium during the α- to β- phase transition, denoting the behavior more similar to the bulk materials than nanoparticles. The stability in the crystal sizes for both α- and β-hydride phases during the phase transition indicates that no sub-domains are formed within a single particle during the phase transition.
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