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Shao K, Mesbah A. A Study on the Role of Electric Field in Low-Temperature Plasma Catalytic Ammonia Synthesis via Integrated Density Functional Theory and Microkinetic Modeling. JACS AU 2024; 4:525-544. [PMID: 38425907 PMCID: PMC10900214 DOI: 10.1021/jacsau.3c00654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 03/02/2024]
Abstract
Low-temperature plasma catalysis has shown promise for various chemical processes such as light hydrocarbon conversion, volatile organic compounds removal, and ammonia synthesis. Plasma-catalytic ammonia synthesis has the potential advantages of leveraging renewable energy and distributed manufacturing principles to mitigate the pressing environmental challenges of the energy-intensive Haber-Bosh process, towards sustainable ammonia production. However, lack of foundational understanding of plasma-catalyst interactions poses a key challenge to optimizing plasma-catalytic processes. Recent studies suggest electro- and photoeffects, such as electric field and charge, can play an important role in enhancing surface reactions. These studies mostly rely on using density functional theory (DFT) to investigate surface reactions under these effects. However, integration of DFT with microkinetic modeling in plasma catalysis, which is crucial for establishing a comprehensive understanding of the interplay between the gas-phase chemistry and surface reactions, remains largely unexplored. This paper presents a first-principles framework coupling DFT calculations and microkinetic modeling to investigate the role of electric field on plasma-catalytic ammonia synthesis. The DFT-microkinetic model shows more consistent predictions with experimental observations, as compared to the case wherein the variable effects of plasma process parameters on surface reactions are neglected. In particular, predictions of the DFT-microkinetic model indicate electric field can have a notable effect on surface reactions relative to other process parameters. A global sensitivity analysis is performed to investigate how ammonia synthesis pathways will change in relation to different plasma process parameters. The DFT-microkinetic model is then used in conjunction with active learning to systematically explore the complex parameter space of the plasma-catalytic ammonia synthesis to maximize the amount of produced ammonia while inhibiting reactions dissipating energy, such as the recombination of H2 through gas-phase H radicals and surface-adsorbed H. This paper demonstrates the importance of accounting for the effects of electric field on surface reactions when investigating and optimizing the performance of plasma-catalytic processes.
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Affiliation(s)
- Ketong Shao
- Department of Chemical & Biomolecular
Engineering, University of California, Berkeley, California 94720, United States
| | - Ali Mesbah
- Department of Chemical & Biomolecular
Engineering, University of California, Berkeley, California 94720, United States
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del Mazo-Sevillano P, Félix-González D, Aguado A, Sanz-Sanz C, Kwon DH, Roncero O. Vibrational, non-adiabatic and isotopic effects in the dynamics of the H 2 + H 2+ → H 3+ + H reaction: application to plasma modelling. Mol Phys 2023. [DOI: 10.1080/00268976.2023.2183071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Affiliation(s)
- P. del Mazo-Sevillano
- Department of Mathematics and Computer Science, FU Berlin, Berlin, Germany
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - D. Félix-González
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - A. Aguado
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - C. Sanz-Sanz
- Unidad Asociada UAM-IFF-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, Madrid, Spain
| | - D.-H. Kwon
- Nuclear Physics Application Research Division, Korea Atomic Energy Research Institute, Daejeon, Republic of Korea
| | - O. Roncero
- Instituto de Física Fundamental, IFF-CSIC, Madrid, Spain
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Merkt F, Höveler K, Deiglmayr J. Reactions of H 2, HD, and D 2 with H 2+, HD +, and D 2+: Product-Channel Branching Ratios and Simple Models. J Phys Chem Lett 2022; 13:864-871. [PMID: 35045261 PMCID: PMC8802320 DOI: 10.1021/acs.jpclett.1c03374] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
We present measurements of the product-channel branching ratios of the reactions (i) HD+ + HD forming H2D+ + D (38.1(30)%) and HD2+ + H (61.9(30)%), (ii) HD+ + D2 forming HD2+ + D (61.4(35)%) and D3+ + H (38.6(35)%), and (iii) D2+ + HD forming HD2++ D (60.5(20)%) and D3+ + H (39.5(20)%) at collision energies Ecoll near zero, i.e., below kB × 1 K. These branching ratios are compared with branching ratios predicted using three simple models: a combinatorial model (M1), a model (M2) describing the reactions as H-, H+-, D-, and D+-transfer processes, and a statistical model (M3) that relates the reaction rate coefficients to the translational and rovibrational state densities of the HnD3-n+ + H/D (n = 0, 1, 2 or 3) product channels. The experimental data are incompatible with the predictions of models M1 and M2 and reveal that the branching ratios exhibit clear correlations with the product state densities.
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Affiliation(s)
- Frédéric Merkt
- Laboratorium für
Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - Katharina Höveler
- Laboratorium für
Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
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Savić I, Schlemmer S, Gerlich D. Formation of H 3 + in Collisions of H 2 + with H 2 Studied in a Guided Ion Beam Instrument. Chemphyschem 2020; 21:1429-1435. [PMID: 32394630 DOI: 10.1002/cphc.202000258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/07/2020] [Indexed: 01/26/2023]
Abstract
In order to study collisions between ions and neutrals, a new Guided Ion Beam (GIB) apparatus, called NOVion, has been assembled and tested. The primary purpose of this instrument is to measure absolute cross sections at energies relevant for technical or inter- and circumstellar plasmas. New and improved results are presented for forming H3 + in collisions of H2 + with H2 . Between 0.1 eV and 2 eV, our measured effective cross sections are in good overall agreement with most previous measurements. However, at higher energies, our results do not show the steep decline, recommended in the standard literature. After critical evaluation of all experimental and theoretical data, a new analytical function is proposed, describing properly the dependence of the title reaction on the collision energy up to 10 eV.
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Affiliation(s)
- Igor Savić
- Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 4, Novi Sad, 21000, Serbia
| | - Stephan Schlemmer
- I. Physikalisches Institut, Universität zu Köln, Zülpicher Straße 77, Köln, 50937, Germany
| | - Dieter Gerlich
- Physikalisches Institut, Technische Universität Chemnitz, Reichenhainer Straße 70, Chemnitz, 09107, Germany
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Jiménez-Redondo M, Tanarro I, Peláez RJ, Díaz-Pérez L, Herrero VJ. Ionic Polymerization in Cold Plasmas of Acetylene with Ar and He. J Phys Chem A 2019; 123:8135-8147. [PMID: 31461278 DOI: 10.1021/acs.jpca.9b06399] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ionic polymerization of acetylene in cold plasmas of C2H2/He and C2H2/Ar has been experimentally studied and modeled in radio frequency (rf) discharges with conditions selected to avoid particle formation. Steady-state distributions of positive and negative ions were measured with mass spectrometry. All the measured distributions are dominated by ions with an even number of carbon atoms, reflecting the characteristic polyyne structures typical for the polymerization of acetylene. The distributions show a monotonic decrease in intensity from ions with two carbon atoms until the highest number of atoms detected. For cations, the distributions extend until 12 carbon atoms. The anion distributions extend further, and negative ions with 20 C atoms are observed in the C2H2/Ar plasma. From the measured mass spectra it is not possible to decide on the possible presence of aromatic species in ions with more than six carbon atoms. A simple model assuming a homogeneous discharge was used to describe the plasma kinetics and could account for the measured ion distributions with reasonable values of charge density and electron temperature. The results of this work stress the important role of the vinylidene anion and indicate that Ar and He do not have much influence on the carbon chemistry.
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Affiliation(s)
| | - Isabel Tanarro
- Instituto de Estructura de la Materia (IEM-CSIC) Serrano 121-123, 28006 Madrid , Spain
| | - Ramón J Peláez
- Instituto de Estructura de la Materia (IEM-CSIC) Serrano 121-123, 28006 Madrid , Spain
| | - Lidia Díaz-Pérez
- Instituto de Estructura de la Materia (IEM-CSIC) Serrano 121-123, 28006 Madrid , Spain
| | - Víctor J Herrero
- Instituto de Estructura de la Materia (IEM-CSIC) Serrano 121-123, 28006 Madrid , Spain
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de Castro A, Valson P, Tabarés F. Hydrogen retention studies on lithiated tungsten exposed to glow discharge plasmas under varying lithiation environments using Thermal Desorption Spectroscopy and mass spectrometry. FUSION ENGINEERING AND DESIGN 2017. [DOI: 10.1016/j.fusengdes.2016.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Jiménez-Redondo M, Carrasco E, Herrero VJ, Tanarro I. Chemistry in glow discharges of H 2 / O 2 mixtures. Diagnostics and modelling. PLASMA SOURCES SCIENCE & TECHNOLOGY 2015; 24:015029. [PMID: 26702195 PMCID: PMC4685741 DOI: 10.1088/0963-0252/24/1/015029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The chemistry of low pressure H2 + O2 discharges with different mixture ratios has been studied in a hollow cathode DC reactor. Neutral and positive ion distributions have been measured by mass spectrometry, and Langmuir probes have been used to provide charge densities and electron temperatures. A simple zero order kinetic model including neutral species and positive and negative ions, which takes into account gas-phase and heterogeneous chemistry, has been used to reproduce the global composition of the plasmas over the whole range of mixtures experimentally studied, and allows for the identification of the main physicochemical mechanisms that may explain the experimental results. To our knowledge, no combined experimental and modelling studies of the heavy species kinetics of low pressure H2 + O2 plasmas including ions has been reported before. As expected, apart from the precursors, H2O is detected in considerable amounts. The model also predicts appreciable concentrations of H and O atoms and the OH radical. The relevance of the metastable species O(1D) and O2(a1Δg) is analysed. Concerning the charged species, positive ion distributions are dominated by H3O+ for a wide range of intermediate mixtures, while H3+ and O2+ are the major ions for the higher and lower H2/O2 ratios, respectively. The mixed ions OH+, H2O+ and HO2+ are also observed in small amounts. Negative ions are shown to have a limited relevance in the global chemistry; their main contribution is the reduction of the electron density available for electron impact processes.
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Affiliation(s)
- M Jiménez-Redondo
- Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid, Spain
| | - E Carrasco
- Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid, Spain
| | - V J Herrero
- Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid, Spain
| | - I Tanarro
- Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid, Spain
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Jiménez-Redondo M, Cueto M, Doménech JL, Tanarro I, Herrero VJ. Ion kinetics in Ar/H 2 cold plasmas: the relevance of ArH .. RSC Adv 2014; 4:62030-62041. [PMID: 26702354 PMCID: PMC4685740 DOI: 10.1039/c4ra13102a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The recent discovery of ArH+ in the interstellar medium has awakened the interest in the chemistry of this ion. In this work, the ion-molecule kinetics of cold plasmas of Ar/H2 is investigated in glow discharges spanning the whole range of [H2]/([H2]+[Ar]) proportions for two pressures, 1.5 and 8 Pa. Ion concentrations are determined by mass spectrometry, and electron temperatures and densities, with Langmuir probes. A kinetic model is used for the interpretation of the results. The selection of experimental conditions evinces relevant changes with plasma pressure in the ion distributions dependence with the H2 fraction, particularly for the major ions: Ar+, ArH+ and H3+. At 1.5 Pa, ArH+ prevails for a wide interval of H2 fractions: 0.3<[H2]/([H2]+[Ar])<0.7. Nevertheless, a pronounced displacement of the ArH+ maximum towards the lowest H2 fractions is observed at 8 Pa, in detriment of Ar+, which becomes restricted to very small [H2]/([H2]+[Ar]) ratios, whereas H3+ becomes dominant for all [H2]/([H2]+[Ar]) > 0.1. The analysis of the data with the kinetic model allows the identification of the sources and sinks of the major ions over the whole range of experimental conditions sampled. Two key factors turn out to be responsible for the different ion distributions observed: the electron temperature, which determines the rate of Ar+ formation and thus of ArH+, and the equilibrium ArH+ + H2 ⇄ H3+ + Ar, which can be strongly dependent of the degree of vibrational excitation of H3+. The results are discussed and compared with previously published data on other Ar/H2 plasmas.
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Affiliation(s)
| | - Maite Cueto
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid, Spain
| | - José Luis Doménech
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid, Spain
| | - Isabel Tanarro
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid, Spain
| | - Víctor J. Herrero
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid, Spain
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Wang F, Zhang X, Wang L, Jiang Y, Wei C, Sun J, Zhao Y. Role of hydrogen plasma pretreatment in improving passivation of the silicon surface for solar cells applications. ACS APPLIED MATERIALS & INTERFACES 2014; 6:15098-15104. [PMID: 25141300 DOI: 10.1021/am5031837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have investigated the role of hydrogen plasma pretreatment in promoting silicon surface passivation, in particular examining its effects on modifying the microstructure of the subsequently deposited thin hydrogenated amorphous silicon (a-Si:H) passivation film. We demonstrate that pretreating the silicon surface with hydrogen plasma for 40 s improves the homogeneity and compactness of the a-Si:H film by enhancing precursor diffusion and thus increasing the minority carrier lifetime (τ(eff)). However, excessive pretreatment also increases the density of dangling bond defects on the surface due to etching effects of the hydrogen plasma. By varying the duration of hydrogen plasma pretreatment in fabricating silicon heterojunction solar cells based on textured substrates, we also demonstrate that, although the performance of the solar cells shows a similar tendency to that of the τ(eff) on polished wafers, the optimal duration is prolonged owing to the differences in the surface morphology of the substrates. These results suggest that the hydrogen plasma condition must be carefully regulated to achieve the optimal level of surface atomic hydrogen coverage and avoid the generation of defects on the silicon wafer.
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Affiliation(s)
- Fengyou Wang
- Institute of Photo-electronics Thin Film Devices and Technique of Nankai University , Key Laboratory of Photo-electronics Thin Film Devices and Technique of Tianjin, Key Laboratory of Photo-Electronic Information Science and Technology of Ministry of Education (Nankai University), Tianjin 300071, China
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Carrasco E, Tanarro I, Herrero VJ, Cernicharo J. Proton transfer chains in cold plasmas of H2with small amounts of N2. The prevalence of NH4+. Phys Chem Chem Phys 2013; 15:1699-706. [PMID: 23247609 DOI: 10.1039/c2cp43438e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Esther Carrasco
- Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, 28006 Madrid, Spain
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Gómez-Carrasco S, González-Sánchez L, Aguado A, Sanz-Sanz C, Zanchet A, Roncero O. Dynamically biased statistical model for the ortho/para conversion in the H2+H3+ → H3++ H2 reaction. J Chem Phys 2012; 137:094303. [DOI: 10.1063/1.4747548] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jambrina PG, Alvariño JM, Gerlich D, Hankel M, Herrero VJ, Sáez-Rábanos V, Aoiz FJ. Dynamics of the D+ + H2 and H+ + D2 reactions: a detailed comparison between theory and experiment. Phys Chem Chem Phys 2012; 14:3346-59. [DOI: 10.1039/c2cp23479c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Carrasco E, Jiménez-Redondo M, Tanarro I, Herrero VJ. Neutral and ion chemistry in low pressure dc plasmas of H2/N2 mixtures: routes for the efficient production of NH3 and NH4+. Phys Chem Chem Phys 2011; 13:19561-72. [DOI: 10.1039/c1cp22284h] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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