1
|
Blackman K, Segrest E, Turner G, Machamer K, Gupta A, Khan Pathan MA, Berriel SN, Banerjee P, Vaida ME. Simultaneous tracking of ultrafast surface and gas-phase dynamics in solid-gas interfacial reactions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:083003. [PMID: 39133084 DOI: 10.1063/5.0217441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 07/21/2024] [Indexed: 08/13/2024]
Abstract
Real-time detection of intermediate species and final products at the surface and near-surface in interfacial solid-gas reactions is critical for an accurate understanding of heterogeneous reaction mechanisms. In this article, an experimental method that can simultaneously monitor the ultrafast dynamics at the surface and above the surface in photoinduced heterogeneous reactions is presented. This method relies on a combination of mass spectrometry and femtosecond pump-probe spectroscopy. As a model system, the photoinduced reaction of methyl iodide on and above a cerium oxide surface is investigated. The species that are simultaneously detected from the surface and gas-phase present distinct features in the mass spectra, such as a sharp peak followed by an adjacent broad shoulder. The sharp peak is attributed to the species detected from the surface, while the broad shoulder is due to the detection of gas-phase species above the surface, as confirmed by multiple experiments. By monitoring the evolution of the sharp peak and broad shoulder as a function of the pump-probe time delay, transient signals are obtained that describe the ultrafast photoinduced reaction dynamics of methyl iodide on the surface and in the gas-phase. Finally, SimION simulations are performed to confirm the origin of the ions produced on the surface and in the gas-phase.
Collapse
Affiliation(s)
- Keith Blackman
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Eric Segrest
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - George Turner
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Kai Machamer
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Aakash Gupta
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - Md Afjal Khan Pathan
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| | - S Novia Berriel
- Department of Material Science and Engineering, University of Central Florida, Orlando, Florida 32816, USA
| | - Parag Banerjee
- Department of Material Science and Engineering, University of Central Florida, Orlando, Florida 32816, USA
- Nano Science and Technology Center, University of Central Florida, Orlando, Florida 32816, USA
- Florida Solar Energy Center, University of Central Florida, Orlando, Florida 32816, USA
- Renewable Energy and Chemical Transformations Cluster, University of Central Florida, Orlando, Florida 32816, USA
| | - Mihai E Vaida
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
- Renewable Energy and Chemical Transformations Cluster, University of Central Florida, Orlando, Florida 32816, USA
| |
Collapse
|
2
|
Pathan MAK, Gupta A, Vaida ME. Understanding the Effect of an Amorphous Surface on the Ultrafast Dynamics of a Heterogeneous Photoinduced Reaction: CD 3I Photoinduced Reaction on Amorphous Cerium Oxide Films. J Phys Chem Lett 2022; 13:9759-9765. [PMID: 36226789 DOI: 10.1021/acs.jpclett.2c02294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In this work, to understand how an amorphous surface influences the dynamics of surface photoinduced reactions, pump-probe spectroscopy in conjunction with mass spectrometry is employed to track the ultrafast evolution of intermediates and final products with time, mass, and energy resolution. As a model system, the photoinduced reaction of CD3I adsorbed on amorphous cerium oxide films is investigated. A fraction of the first intermediates produced on a freshly prepared surface is trapped to passivate the surface. After the A-band excitation, the minimum dissociation time of CD3I indicates that CD3I adsorption geometries with either CD3 or I facing the gas phase exist; however, the transient data suggest that most molecules are adsorbed with the I atom facing the surface. CD3 and I are consumed to form I2 and reform CD3I, which are produced at a steady rate only after the intermediates have lost the excess translational energy released from photodissociation.
Collapse
Affiliation(s)
- Md Afjal Khan Pathan
- Department of Physics, University of Central Florida, Orlando, Florida32816, United States
| | - Aakash Gupta
- Department of Physics, University of Central Florida, Orlando, Florida32816, United States
| | - Mihai E Vaida
- Department of Physics, University of Central Florida, Orlando, Florida32816, United States
- Renewable Energy and Chemical Transformations Cluster, University of Central Florida, Orlando, Florida32816, United States
| |
Collapse
|
3
|
Muraca AR, Kershis MD, Camillone N, White MG. Ultrafast dynamics of acetone photooxidation on TiO2(110). J Chem Phys 2019; 151:161103. [DOI: 10.1063/1.5122269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Amanda R. Muraca
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
| | - Matthew D. Kershis
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Nicholas Camillone
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Michael G. White
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, USA
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, USA
| |
Collapse
|
4
|
Gunzer F, Krüger S, Grotemeyer J. Photoionization and photofragmentation in mass spectrometry with visible and UV lasers. MASS SPECTROMETRY REVIEWS 2019; 38:202-217. [PMID: 30300954 DOI: 10.1002/mas.21579] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 08/29/2018] [Indexed: 06/08/2023]
Abstract
Ever since the introduction of laser technology to the field of mass spectrometry, several disciplines evolved providing solutions to challenging scientific and analytical tasks in research and industry. Among these are techniques involving multiphoton ionization such as Resonance-Enhanced Multiphoton Ionization (REMPI, R2PI) and Mass-Analyzed Threshold Ionization (MATI) spectroscopy, a variant of Zero Kinetic Energy (ZEKE) spectroscopy, that possess the ability to selectively ionize certain preselected compounds out of complex mixtures, for example, environmental matrices, with a high level of efficiency. Another key feature of multiphoton ionization techniques is the ability to control the degree of fragmentation, whereas soft ionization is most highly appreciated in most applications. In cases where rich fragmentation patterns are desired for diagnostic purposes, Photodissociation mass spectrometry (PD-MS) is applied successfully. PD-MS allows for the cleavage of selected chemical bonds. With the introduction of chromophoric labels in PD-MS, it became possible to target certain molecules or groups within a molecule. In this review article, an overview of the basic principles and experimental requirements of REMPI and MATI spectroscopy and PD mass spectrometry are given. By means of selected examples, the latest developments and application possibilities in this field over the past decade with special focus on the German research landscape are pointed out. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 38: 202-217, 2019.
Collapse
Affiliation(s)
- Frank Gunzer
- Physics Department, German University in Cairo, New Cairo City, Cairo, Egypt
| | - Sascha Krüger
- Department for Laser Mass Spectrometry, Institute for Physical Chemistry, Christian-Albrecht-University Kiel, Max-Eyth-Strasse 1, 24118 Kiel, Germany
| | - Jürgen Grotemeyer
- Department for Laser Mass Spectrometry, Institute for Physical Chemistry, Christian-Albrecht-University Kiel, Max-Eyth-Strasse 1, 24118 Kiel, Germany
| |
Collapse
|
5
|
Vaida ME, Bernhardt TM. Tuning the ultrafast photodissociation dynamics of CH 3 Br on ultrathin MgO films by reducing the layer thickness to the 2D limit. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.09.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
6
|
Tracing dissociation dynamics of CH3Br in the 3Q0 state with femtosecond extreme ultraviolet ionization. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2014.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
7
|
Vaida ME, Bernhardt TM. Surface-Aligned Femtochemistry: Molecular Reaction Dynamics on Oxide Surfaces. SPRINGER SERIES IN CHEMICAL PHYSICS 2014. [DOI: 10.1007/978-3-319-02051-8_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
8
|
|
9
|
Leung L, Lim T, Ning Z, Polanyi JC. Localized Reaction at a Smooth Metal Surface: p-Diiodobenzene at Cu(110). J Am Chem Soc 2012; 134:9320-6. [DOI: 10.1021/ja301608q] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lydie Leung
- Lash Miller Chemical Laboratories,
Department of Chemistry
and Institute of Optical Science, University of Toronto, 80 St. George Street, Ontario M5S 3H6, Canada
| | - Tingbin Lim
- Lash Miller Chemical Laboratories,
Department of Chemistry
and Institute of Optical Science, University of Toronto, 80 St. George Street, Ontario M5S 3H6, Canada
| | - Zhanyu Ning
- Lash Miller Chemical Laboratories,
Department of Chemistry
and Institute of Optical Science, University of Toronto, 80 St. George Street, Ontario M5S 3H6, Canada
| | - John C. Polanyi
- Lash Miller Chemical Laboratories,
Department of Chemistry
and Institute of Optical Science, University of Toronto, 80 St. George Street, Ontario M5S 3H6, Canada
| |
Collapse
|
10
|
Vaida ME, Bernhardt TM. Surface-aligned femtochemistry: Photoinduced reaction dynamics of CH3I and CH3Br on MgO(100). Faraday Discuss 2012; 157:437-49; discussion 475-500. [DOI: 10.1039/c2fd20104f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
11
|
Eisenstein A, Leung L, Lim T, Ning Z, Polanyi JC. Reaction dynamics at a metal surface; halogenation of Cu(110). Faraday Discuss 2012; 157:337-53; discussion 375-98. [DOI: 10.1039/c2fd20023f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Vaida ME, Tchitnga R, Bernhardt TM. Femtosecond time-resolved photodissociation dynamics of methyl halide molecules on ultrathin gold films. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2011; 2:618-27. [PMID: 22003467 PMCID: PMC3190631 DOI: 10.3762/bjnano.2.65] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 09/16/2011] [Indexed: 05/12/2023]
Abstract
The photodissociation of small organic molecules, namely methyl iodide, methyl bromide, and methyl chloride, adsorbed on a metal surface was investigated in real time by means of femtosecond-laser pump-probe mass spectrometry. A weakly interacting gold surface was employed as substrate because the intact adsorption of the methyl halide molecules was desired prior to photoexcitation. The gold surface was prepared as an ultrathin film on Mo(100). The molecular adsorption behavior was characterized by coverage dependent temperature programmed desorption spectroscopy. Submonolayer preparations were irradiated with UV light of 266 nm wavelength and the subsequently emerging methyl fragments were probed by photoionization and mass spectrometric detection. A strong dependence of the excitation mechanism and the light-induced dynamics on the type of molecule was observed. Possible photoexcitation mechanisms included direct photoexcitation to the dissociative A-band of the methyl halide molecules as well as the attachment of surface-emitted electrons with transient negative ion formation and subsequent molecular fragmentation. Both reaction pathways were energetically possible in the case of methyl iodide, yet, no methyl fragments were observed. As a likely explanation, the rapid quenching of the excited states prior to fragmentation is proposed. This quenching mechanism could be prevented by modification of the gold surface through pre-adsorption of iodine atoms. In contrast, the A-band of methyl bromide was not energetically directly accessible through 266 nm excitation. Nevertheless, the one-photon-induced dissociation was observed in the case of methyl bromide. This was interpreted as being due to a considerable energetic down-shift of the electronic A-band states of methyl bromide by about 1.5 eV through interaction with the gold substrate. Finally, for methyl chloride no photofragmentation could be detected at all.
Collapse
Affiliation(s)
- Mihai E Vaida
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
| | - Robert Tchitnga
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
| | - Thorsten M Bernhardt
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
| |
Collapse
|
13
|
Vaida ME, Bernhardt TM. Surface pump-probe femtosecond-laser mass spectrometry: time-, mass-, and velocity-resolved detection of surface reaction dynamics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:104103. [PMID: 21034102 DOI: 10.1063/1.3488098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A detailed account of the experimental methodology of surface pump-probe femtosecond-laser mass spectrometry is presented. This recently introduced technique enables the direct time-resolved investigation of surface reaction dynamics by monitoring the mass and the relative velocity of intermediates and products of a photoinduced surface reaction via multiphoton ionization. As a model system, the photodissociation dynamics of methyl iodide adsorbed at submonolayer coverage on magnesia ultrathin films is investigated. The magnesia surface preparation and characterization as well as the pulsed deposition of methyl iodide are described. The femtosecond-laser excitation (pump) and, in particular, the resonant multiphoton ionization surface detection (probe) schemas are discussed in detail. Results of pump-probe time-resolved methyl and iodine atom detection experiments are presented and the potential of this method for velocity-resolved photofragment analysis is evaluated.
Collapse
Affiliation(s)
- Mihai E Vaida
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
| | | |
Collapse
|