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Roy S, K. J. N, Tiwari N, Tiwari AK. Energetics and dynamics of CH4 and H2O dissociation on metal surfaces. INT REV PHYS CHEM 2020. [DOI: 10.1080/0144235x.2020.1765598] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Sudipta Roy
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Nayanthara K. J.
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Nidhi Tiwari
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
| | - Ashwani K. Tiwari
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, India
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Gutiérrez-González A, Beck RD. Quantum state and surface-site-resolved studies of methane chemisorption by vibrational spectroscopies. Phys Chem Chem Phys 2020; 22:17448-17459. [DOI: 10.1039/d0cp03134h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infrared spectroscopic methods enable quantum-state-specific and surface-site-selective studies of methane chemisorption on stepped platinum surfaces.
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Affiliation(s)
- Ana Gutiérrez-González
- Laboratoire de Chimie Physique Moléculaire (LCPM)
- École Polytechnique Fédérale de Lausanne (EPFL)
- CH-1015 Lausanne
- Switzerland
| | - Rainer D. Beck
- Laboratoire de Chimie Physique Moléculaire (LCPM)
- École Polytechnique Fédérale de Lausanne (EPFL)
- CH-1015 Lausanne
- Switzerland
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4
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Wang W, Zhao Y. The dissociation and recombination rates of CH 4 through the Ni(111) surface: The effect of lattice motion. J Chem Phys 2017; 147:044703. [PMID: 28764359 DOI: 10.1063/1.4995299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Methane dissociation is a prototypical system for the study of surface reaction dynamics. The dissociation and recombination rates of CH4 through the Ni(111) surface are calculated by using the quantum instanton method with an analytical potential energy surface. The Ni(111) lattice is treated rigidly, classically, and quantum mechanically so as to reveal the effect of lattice motion. The results demonstrate that it is the lateral displacements rather than the upward and downward movements of the surface nickel atoms that affect the rates a lot. Compared with the rigid lattice, the classical relaxation of the lattice can increase the rates by lowering the free energy barriers. For instance, at 300 K, the dissociation and recombination rates with the classical lattice exceed the ones with the rigid lattice by 6 and 10 orders of magnitude, respectively. Compared with the classical lattice, the quantum delocalization rather than the zero-point energy of the Ni atoms further enhances the rates by widening the reaction path. For instance, the dissociation rate with the quantum lattice is about 10 times larger than that with the classical lattice at 300 K. On the rigid lattice, due to the zero-point energy difference between CH4 and CD4, the kinetic isotope effects are larger than 1 for the dissociation process, while they are smaller than 1 for the recombination process. The increasing kinetic isotope effect with decreasing temperature demonstrates that the quantum tunneling effect is remarkable for the dissociation process.
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Affiliation(s)
- Wenji Wang
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100 Shaanxi Province, People's Republic of China
| | - Yi Zhao
- State Key Laboratory for Physical Chemistry of Solid Surfaces and Fujian Provincial Key Lab of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China
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5
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Shen X, Zhang Z, Zhang DH. Methane dissociation on Ni(111): A seven-dimensional to nine-dimensional quantum dynamics study. J Chem Phys 2017; 147:024702. [DOI: 10.1063/1.4991562] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Xiangjian Shen
- Research Center of Heterogeneous Catalysis and Engineering Sciences, School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou 450001, China
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
| | - Zhaojun Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
| | - Dong H. Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
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6
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Hundt PM, van Reijzen ME, Beck RD, Guo H, Jackson B. Quantum-state-resolved reactivity of overtone excited CH4on Ni(111): Comparing experiment and theory. J Chem Phys 2017; 146:054701. [DOI: 10.1063/1.4975025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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7
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Shen X, Chen J, Zhang Z, Shao K, Zhang DH. Methane dissociation on Ni(111): A fifteen-dimensional potential energy surface using neural network method. J Chem Phys 2016; 143:144701. [PMID: 26472389 DOI: 10.1063/1.4932226] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In the present work, we develop a highly accurate, fifteen-dimensional potential energy surface (PES) of CH4 interacting on a rigid flat Ni(111) surface with the methodology of neural network (NN) fit to a database consisted of about 194 208 ab initio density functional theory (DFT) energy points. Some careful tests of the accuracy of the fitting PES are given through the descriptions of the fitting quality, vibrational spectrum of CH4 in vacuum, transition state (TS) geometries as well as the activation barriers. Using a 25-60-60-1 NN structure, we obtain one of the best PESs with the least root mean square errors: 10.11 meV for the entrance region and 17.00 meV for the interaction and product regions. Our PES can reproduce the DFT results very well in particular for the important TS structures. Furthermore, we present the sticking probability S0 of ground state CH4 at the experimental surface temperature using some sudden approximations by Jackson's group. An in-depth explanation is given for the underestimated sticking probability.
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Affiliation(s)
- Xiangjian Shen
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Jun Chen
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Zhaojun Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Kejie Shao
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Dong H Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
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8
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Jiang B, Yang M, Xie D, Guo H. Quantum dynamics of polyatomic dissociative chemisorption on transition metal surfaces: mode specificity and bond selectivity. Chem Soc Rev 2016; 45:3621-40. [DOI: 10.1039/c5cs00360a] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent advances in quantum dynamical characterization of polyatomic dissociative chemisorption on accurate global potential energy surfaces are critically reviewed.
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Affiliation(s)
- Bin Jiang
- Department of Chemistry and Chemical Biology
- University of New Mexico
- Albuquerque
- USA
- Department of Chemical Physics
| | - Minghui Yang
- Key Laboratory of Magnetic Resonance in Biological Systems
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics
- Wuhan Centre for Magnetic Resonance
- Wuhan Institute of Physics and Mathematics
- Chinese Academy of Sciences
| | - Daiqian Xie
- Institute of Theoretical and Computational Chemistry
- Key Laboratory of Mesoscopic Chemistry
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Hua Guo
- Department of Chemistry and Chemical Biology
- University of New Mexico
- Albuquerque
- USA
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9
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Campbell VL, Chen N, Guo H, Jackson B, Utz AL. Substrate Vibrations as Promoters of Chemical Reactivity on Metal Surfaces. J Phys Chem A 2015; 119:12434-41. [DOI: 10.1021/acs.jpca.5b07873] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Victoria L. Campbell
- Department
of Chemistry and W. M. Keck Foundation Laboratory for Materials Chemistry Tufts University, Medford, Massachusetts 02155, United States
| | - Nan Chen
- Department
of Chemistry and W. M. Keck Foundation Laboratory for Materials Chemistry Tufts University, Medford, Massachusetts 02155, United States
| | - Han Guo
- Department
of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Bret Jackson
- Department
of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Arthur L. Utz
- Department
of Chemistry and W. M. Keck Foundation Laboratory for Materials Chemistry Tufts University, Medford, Massachusetts 02155, United States
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10
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Shen X, Zhang Z, Zhang DH. CH4 dissociation on Ni(111): a quantum dynamics study of lattice thermal motion. Phys Chem Chem Phys 2015; 17:25499-504. [DOI: 10.1039/c5cp04229a] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lattice thermal motion is of great importance because it has a significant effect on molecule activation on metal surfaces.
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Affiliation(s)
- Xiangjian Shen
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- P. R. China
| | - Zhaojun Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- P. R. China
| | - Dong H. Zhang
- State Key Laboratory of Molecular Reaction Dynamics and Center for Theoretical Computational Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- P. R. China
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11
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Nave S, Tiwari AK, Jackson B. Dissociative Chemisorption of Methane on Ni and Pt Surfaces: Mode-Specific Chemistry and the Effects of Lattice Motion. J Phys Chem A 2014; 118:9615-31. [DOI: 10.1021/jp5063644] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sven Nave
- Institut des Sciences
Moléculaires d’Orsay, Université Paris-Sud 11/CNRS-UMR
8214, Université Paris-Sud, Bât. 351, 91405 Orsay Cedex, France
| | - Ashwani K. Tiwari
- Indian Institute of Science Education and Research Kolkata, Mohanpur 741252, India
| | - Bret Jackson
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, United States
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12
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Donald SB, Navin JK, Harrison I. Methane dissociative chemisorption and detailed balance on Pt(111): dynamical constraints and the modest influence of tunneling. J Chem Phys 2014; 139:214707. [PMID: 24320394 DOI: 10.1063/1.4837697] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A dynamically biased (d-) precursor mediated microcanonical trapping (PMMT) model of the activated dissociative chemisorption of methane on Pt(111) is applied to a wide range of dissociative sticking experiments, and, by detailed balance, to the methane product state distributions from the thermal associative desorption of adsorbed hydrogen with coadsorbed methyl radicals. Tunneling pathways were incorporated into the d-PMMT model to better replicate the translational energy distribution of the desorbing methane product from the laser induced thermal reaction of coadsorbed hydrogen and methyl radicals occurring near T(s) = 395 K. Although tunneling is predicted to be inconsequential to the thermal dissociative chemisorption of CH4 on Pt(111) at the high temperatures of catalytic interest, once the temperature drops to 395 K the tunneling fraction of the reactive thermal flux reaches 15%, and as temperatures drop below 275 K the tunneling fraction exceeds 50%. The d-PMMT model parameters of {E0 = 58.9 kJ/mol, s = 2, η(v) = 0.40} describe the apparent threshold energy for CH4/Pt(111) dissociative chemisorption, the number of surface oscillators involved in the precursor complex, and the efficacy of molecular vibrational energy to promote reaction, relative to translational energy directed along the surface normal. Molecular translations parallel to the surface and rotations are treated as spectator degrees of freedom. Transition state vibrational frequencies are derived from generalized gradient approximation-density functional theory electronic structure calculations. The d-PMMT model replicates the diverse range of experimental data available with good fidelity, including some new effusive molecular beam and ambient gas dissociative sticking measurements. Nevertheless, there are some indications that closer agreement between theory and experiments could be achieved if a surface efficacy less than one was introduced into the modeling as an additional dynamical constraint.
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Affiliation(s)
- S B Donald
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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14
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Killelea DR, Utz AL. On the origin of mode- and bond-selectivity in vibrationally mediated reactions on surfaces. Phys Chem Chem Phys 2013; 15:20545-54. [DOI: 10.1039/c3cp53765j] [Citation(s) in RCA: 30] [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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15
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Chen JC, Ramos M, Arasa C, Juanes-Marcos JC, Somers MF, Martínez AE, Díaz C, Olsen RA, Kroes GJ. Dynamics of H2 dissociation on the 1/2 ML c(2 × 2)-Ti/Al(100) surface. Phys Chem Chem Phys 2012; 14:3234-47. [PMID: 22294155 DOI: 10.1039/c2cp23693a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dissociation of H(2) on Ti-covered Al surfaces is relevant to the rehydrogenation and dehydrogenation of the NaAlH(4) hydrogen storage material. The energetically most stable structure for a 1/2 monolayer of Ti deposited on the Al(100) surface has the Ti atoms in the second layer with a c(2 × 2) structure, as has been confirmed by both low-energy electron diffraction and low-energy ion scattering experiments and density functional theory studies. In this work, we investigate the dynamics of H(2) dissociation on a slab model of this Ti/Al(100) surface. Two six-dimensional potential energy surfaces (PESs) have been built for this H(2) + Ti/Al(100) system, based on the density functional theory PW91 and RPBE exchange-correlation functionals. In the PW91 (RPBE) PES, the lowest H(2) dissociation barrier is found to be 0.65 (0.84) eV, with the minimum energy path occurring for H(2) dissociating above the bridge to top sites. Using both PESs, H(2) dissociation probabilities are calculated using the classical trajectory (CT), the quasi-classical trajectory (QCT), and the time-dependent wave-packet methods. We find that the QCT H(2) dissociation probabilities are in good agreement with the quantum dynamics results in the collision energy range studied up to 1.0 eV. We have also performed molecular beam simulations and present predictions for molecular beam experiments. Our molecular beam simulations show that H(2) dissociation on the 1/2 ML Ti/Al(100) surface is an activated process, and the reaction probability is found to be 6.9% for the PW91 functional and 1.8% for the RPBE at a nozzle temperature of 1700 K. Finally, we have also calculated H(2) dissociation rate constants by applying transition state theory and the QCT method, which could be relevant to modeling Ti-catalyzed rehydrogenation and dehydrogenation of NaAlH(4).
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Affiliation(s)
- Jian-Cheng Chen
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
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Bukoski A. Proper theoretical analysis of the oxygen wash-in kinetics of circle breathing systems. Vet Anaesth Analg 2012; 39:185-9. [PMID: 22252241 DOI: 10.1111/j.1467-2995.2011.00674.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To correctly define the theoretical treatment of oxygen wash-in kinetics in circle breathing systems and reevaluate previously published results for the rate of change of oxygen concentration in a large animal circle breathing system. STUDY DESIGN Theoretical analysis of previously published data. ANIMALS None. METHODS Previously published data for the rate of change of oxygen concentration in a large animal circle breathing system with two reservoir bag sizes (40 and 20 L) at three different flow rates (3, 6, and 10 L minute(-1)) were obtained from the original publication, via digital extraction, and analyzed to determine system time constants. The results of this analysis were compared to those originally reported and the level of mathematical agreement between experiment and theory was quantified. RESULTS Theoretical time constants for the system with 40 L reservoir bag with flow rates of 3, 6, and 10 L minute(-1) were 16.4, 8.2, and 4.9 minutes, respectively. Experimentally derived time constants for this system with flow rates of 3, 6, and 10 L minute(-1) were 18.1, 9.2, and 5.4 minutes, respectively. Percent differences between experimental and theoretical time constants for this system with flow rates of 3, 6, and 10 L minute(-1) were 10.4, 12.2, and 10.2%, respectively. For the system with a 20 L reservoir bag and 6 L minute(-1) flow rate, the theoretical and experimentally derived time constants were 5.5 and 5.6 minutes, respectively, with a 1.8% difference. The average relative deviations between theory and experiment for the system at 6 L minute(-1) flow with a 40 or 20 L reservoir bag were 1.3% and 3.0%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Proper theoretical analysis of experimentally obtained data for the wash-in kinetics of oxygen into a large animal circle breathing system leads to improved mathematical agreement between theory and experiment when compared to the originally published results. Application of this method should allow more accurate prediction of the rate of change of oxygen concentration in anesthetic circuits.
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Affiliation(s)
- Alex Bukoski
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
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Donald SB, Harrison I. Dynamically biased RRKM model of activated gas-surface reactivity: vibrational efficacy and rotation as a spectator in the dissociative chemisorption of CH4on Pt(111). Phys Chem Chem Phys 2012; 14:1784-95. [DOI: 10.1039/c2cp22895e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jackson B, Nave S. The dissociative chemisorption of methane on Ni(100): Reaction path description of mode-selective chemistry. J Chem Phys 2011; 135:114701. [DOI: 10.1063/1.3634073] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Cushing GW, Navin JK, Valadez L, Johánek V, Harrison I. An effusive molecular beam technique for studies of polyatomic gas-surface reactivity and energy transfer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:044102. [PMID: 21529024 DOI: 10.1063/1.3577076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An effusive molecular beam technique is described to measure alkane dissociative sticking coefficients, S(T(g), T(s); ϑ), on metal surfaces for which the impinging gas temperature, T(g), and surface temperature, T(s), can be independently varied, along with the angle of incidence, ϑ, of the impinging gas. Effusive beam experiments with T(g) = T(s) = T allow for determination of angle-resolved dissociative sticking coefficients, S(T; ϑ), which when averaged over the cos (ϑ)/π angular distribution appropriate to the impinging flux from a thermal ambient gas yield the thermal dissociative sticking coefficient, S(T). Nonequilibrium S(T(g), T(s); ϑ) measurements for which T(g) ≠ T(s) provide additional opportunities to characterize the transition state and gas-surface energy transfer at reactive energies. A resistively heated effusive molecular beam doser controls the T(g) of the impinging gas striking the surface. The flux of molecules striking the surface from the effusive beam is determined from knowledge of the dosing geometry, chamber pressure, and pumping speed. Separate experiments with a calibrated leak serve to fix the chamber pumping speed. Postdosing Auger electron spectroscopy is used to measure the carbon of the alkyl radical reaction product that is deposited on the surface as a result of alkane dissociative sticking. As implemented in a typical ultrahigh vacuum chamber for surface analysis, the technique has provided access to a dynamic range of roughly 6 orders of magnitude in the initial dissociative sticking coefficient for small alkanes on Pt(111).
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Affiliation(s)
- G W Cushing
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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20
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Chen JC, Juanes-Marcos JC, Woittequand S, Somers MF, Díaz C, Olsen RA, Kroes GJ. Six-dimensional quasiclassical and quantum dynamics of H2 dissociation on the c(2 × 2)-Ti/Al(100) surface. J Chem Phys 2011; 134:114708. [DOI: 10.1063/1.3567397] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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21
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Yoder BL, Bisson R, Beck RD. Steric Effects in the Chemisorption of Vibrationally Excited Methane on Ni(100). Science 2010; 329:553-6. [DOI: 10.1126/science.1191751] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Bruce L. Yoder
- Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Régis Bisson
- Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rainer D. Beck
- Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Tiwari AK, Nave S, Jackson B. The temperature dependence of methane dissociation on Ni(111) and Pt(111): Mixed quantum-classical studies of the lattice response. J Chem Phys 2010; 132:134702. [DOI: 10.1063/1.3357415] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Killelea DR, Campbell VL, Shuman NS, Utz AL. Bond-Selective Control of a Heterogeneously Catalyzed Reaction. Science 2008; 319:790-3. [DOI: 10.1126/science.1152819] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Nave S, Jackson B. Methane dissociation on Ni(111): The effects of lattice motion and relaxation on reactivity. J Chem Phys 2007; 127:224702. [DOI: 10.1063/1.2800661] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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25
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Abbott HL, Harrison I. Microcanonical Transition State Theory for Activated Gas−Surface Reaction Dynamics: Application to H2/Cu(111) with Rotation as a Spectator. J Phys Chem A 2007; 111:9871-83. [PMID: 17845015 DOI: 10.1021/jp074038a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A microcanonical unimolecular rate theory (MURT) model incorporating quantized surface vibrations and Rice-Ramsperger-Kassel-Marcus rate constants is applied to a benchmark system for gas-surface reaction dynamics, the activated dissociative chemisorption and associative desorption of hydrogen on Cu(111). Both molecular translation parallel to the surface and rotation are treated as spectator degrees of freedom. MURT analysis of diverse experiments indicates that one surface oscillator participates in the dissociative transition state and that the threshold energy for H2 dissociation on Cu(111) is E0 = 62 kJ/mol. The spectator approximation for rotation holds well at thermally accessible rotational energies (i.e., for Er less than approximately 40 kJ/mol). Over the temperature range from 300 to 1000 K, the calculated thermal dissociative sticking coefficient is ST = S0 exp(-Ea/kBT) where S0 = 1.57 and Ea = 62.9 kJ/mol. The sigmoid shape of rovibrational eigenstate-resolved dissociative sticking coefficients as a function of normal translational energy is shown to derive from an averaging of the microcanonical sticking coefficient, with threshold energy E0, over the thermal surface oscillator distribution of the gas-surface collision complexes. Given that H2/Cu(111) is one of the most dynamically biased of gas-surface reactive systems, the simple statistical MURT model simulates and broadly rationalizes the H2/Cu(111) reactive behavior with remarkable fidelity.
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Affiliation(s)
- Heather L Abbott
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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Nave S, Jackson B. Methane dissociation on Ni(111): the role of lattice reconstruction. PHYSICAL REVIEW LETTERS 2007; 98:173003. [PMID: 17501491 DOI: 10.1103/physrevlett.98.173003] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Indexed: 05/11/2023]
Abstract
The effects of lattice motion and reconstruction on the dissociation of methane on Ni(111) are explored, using both electronic structure theory and quantum dynamical calculations. We show that during the reaction, the Ni lattice reconstructs, effectively lowering the barrier to reaction, in contrast with earlier models of this process.
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Affiliation(s)
- Sven Nave
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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Abbott HL, Harrison I. Seven-dimensional microcanonical treatment of hydrogen dissociation dynamics on Cu(111): Clarifying the essential role of surface phonons. J Chem Phys 2006; 125:24704. [PMID: 16848601 DOI: 10.1063/1.2208362] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A simple picture of the hydrogen dissociation/associative desorption dynamics on Cu(111) emerges from a two-parameter, full dimensionality microcanonical unimolecular rate theory (MURT) model of the gas-surface reactivity. Vibrational frequencies for the reactive transition state were taken from density functional theory calculations of a six-dimensional potential energy surface [Hammer et al., Phys. Rev. Lett. 73, 1400 (1994)]. The two remaining parameters required by the MURT were fixed by simulation of experiments. These parameters are the dissociation threshold energy, E(0)=79 kJmol, and the number of surface oscillators involved in the localized H(2)Cu(111) collision complex, s=1. The two-parameter MURT quantitatively predicts much of the varied behavior observed for the H(2) and D(2)Cu(111) reactive systems, including the temperature-dependent associative desorption angular distributions, mean translational energies of the associatively desorbing hydrogen as a function of rovibrational eigenstate, etc. The divergence of the statistical theory's predictions from experimental results at low rotational quantum numbers, J < or approximately 5, suggests that either (i) rotational steering is important to the dissociation dynamics at low J, an effect that washes out at high J, or (ii) molecular rotation is approximately a spectator degree of freedom to the dissociation dynamics for these low J states, the states that dominate the thermal reactivity. Surface vibrations are predicted to provide approximately 30% of the energy required to surmount the activation barrier to H(2) dissociation under thermal equilibrium conditions. The MURT with s=1 is used to analytically confirm the experimental finding that partial differential "E(a)(T(s))" partial differential E(t)= -1 for eigenstate-resolved dissociative sticking at translational energies E(t)<E(0)-E(v)-E(r). Explicit treatment of the surface motion (i.e., surface not frozen at T(s)=0 K) is a relatively novel aspect of the MURT theoretical approach.
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Affiliation(s)
- H L Abbott
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904-4319, USA
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DeWitt KM, Valadez L, Abbott HL, Kolasinski KW, Harrison I. Using Effusive Molecular Beams and Microcanonical Unimolecular Rate Theory to Characterize CH4 Dissociation on Pt(111). J Phys Chem B 2006; 110:6705-13. [PMID: 16570976 DOI: 10.1021/jp0566865] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dissociative sticking coefficient for CH4 on Pt(111) has been measured as a function of both gas temperature (Tg) and surface temperature (Ts) using effusive molecular beam and angle-integrated ambient gas dosing methods. The experimental results are used to optimize the three parameters of a microcanonical unimolecular rate theory (MURT) model of the reactive system. The MURT calculations allow us to extract transition state properties from the data as well as to compare our data directly to other molecular beam and thermal equilibrium sticking measurements. We find a threshold energy for dissociation of E0 = 52.5 +/- 3.5 kJ mol(-1). Furthermore, the MURT with an optimized parameter set provides for a predictive understanding of the kinetics of this C-H bond activation reaction, that is, it allows us to predict the dissociative sticking coefficient of CH4 on Pt(111) for any combination of Ts and Tg even if the two are not equal to one another, indeed, the distribution of molecular energy need not even be thermal. Comparison of our results to those from recent thermal equilibrium catalysis studies on CH4 reforming over Pt nanoclusters ( approximately 2 nm diam) dispersed on oxide substrates indicates that the reactivity of Pt(111) exceeds that of the Pt nanocatalysts by several orders of magnitude.
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Affiliation(s)
- Kristy M DeWitt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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DeWitt KM, Valadez L, Abbott HL, Kolasinski KW, Harrison I. Effusive Molecular Beam Study of C2H6 Dissociation on Pt(111). J Phys Chem B 2006; 110:6714-20. [PMID: 16570977 DOI: 10.1021/jp055684h] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dissociative sticking coefficient for C2H6 on Pt(111) has been measured as a function of both gas temperature (Tg) and surface temperature (Ts) using effusive molecular beam and angle-integrated ambient gas dosing methods. A microcanonical unimolecular rate theory (MURT) model of the reactive system is used to extract transition state properties from the data as well as to compare our data directly with supersonic molecular beam and thermal equilibrium sticking measurements. We report for the first time the threshold energy for dissociation, E0 = 26.5 +/- 3 kJ mol(-1). This value is only weakly dependent on the other two parameters of the model. A strong surface temperature dependence in the initial sticking coefficient is observed; however, the relatively weak dependence on gas temperature indicates some combination of the following (i) not all molecular excitations are contributing equally to the enhancement of sticking, (ii) that strong entropic effects in the dissociative transition state are leading to unusually high vibrational frequencies in the transition state, and (iii) energy transfer from gas-phase rovibrational modes to the surface is surprisingly efficient. In other words, it appears that vibrational mode-specific behavior and/or molecular rotations may play stronger roles in the dissociative adsorption of C2H6 than they do for CH4. The MURT with an optimized parameter set provides for a predictive understanding of the kinetics of this C-H bond activation reaction, that is, it allows us to predict the dissociative sticking coefficient of C2H6 on Pt(111) for any combination of Ts and Tg even if the two are not equal to one another.
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Affiliation(s)
- Kristy M DeWitt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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Bukoski A, Abbott HL, Harrison I. Microcanonical unimolecular rate theory at surfaces. III. Thermal dissociative chemisorption of methane on Pt(111) and detailed balance. J Chem Phys 2005; 123:94707. [PMID: 16164362 DOI: 10.1063/1.2006679] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A local hot spot model of gas-surface reactivity is used to investigate the state-resolved dynamics of methane dissociative chemisorption on Pt(111) under thermal equilibrium conditions. Three Pt surface oscillators, and the molecular vibrations, rotations, and the translational energy directed along the surface normal are treated as active degrees of freedom in the 16-dimensional microcanonical kinetics. Several energy transfer models for coupling a local hot spot to the surrounding substrate are developed and evaluated within the context of a master equation kinetics approach. Bounds on the thermal dissociative sticking coefficient based on limiting energy transfer models are derived. The three-parameter physisorbed complex microcanonical unimolecular rate theory (PC-MURT) is shown to closely approximate the thermal sticking under any realistic energy transfer model. Assuming an apparent threshold energy for CH(4) dissociative chemisorption of E(0)=0.61 eV on clean Pt(111), the PC-MURT is used to predict angle-resolved yield, translational, vibrational, and rotational distributions for the reactive methane flux at thermal equilibrium at 500 K. By detailed balance, these same distributions should be observed for the methane product from methyl radical hydrogenation at 500 K in the zero coverage limit if the methyl radicals are not subject to side reactions. Given that methyl radical hydrogenation can only be experimentally observed when the CH(3) radicals are kinetically stabilized against decomposition by coadsorbed H, the PC-MURT was used to evaluate E(0) in the high coverage limit. A high coverage value of E(0)=2.3 eV adequately reproduced the experimentally observed methane angular and translational energy distributions from thermal hydrogenation of methyl radicals. Although rigorous application of detailed balance arguments to this reactive system cannot be made because thermal decomposition of the methyl radicals competes with hydrogenation, approximate applicability of detailed balance would argue for a strong coverage dependence of E(0) with H coverage--a dependence not seen for methyl radical hydrogenation on Ru(0001), but not yet experimentally explored on Pt(111).
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Affiliation(s)
- A Bukoski
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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Abbott HL, Harrison I. Dissociative chemisorption and energy transfer for methane on Ir(111). J Phys Chem B 2005; 109:10371-80. [PMID: 16852257 DOI: 10.1021/jp0505375] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A 3-parameter local hot spot model of gas-surface reactivity is employed to analyze and predict dissociative sticking coefficients for CH(4) incident on Ir(111) under varied nonequilibrium and equilibrium conditions. One Ir surface oscillator and the molecular vibrations, rotations, and translational energy directed along the surface normal are treated as active degrees of freedom in the 14 dimensional microcanonical kinetics. The threshold energy for CH(4) dissociative chemisorption on Ir(111) derived from modeling molecular beam experiments is E(0) = 39 kJ/mol. Over more than 4 orders of magnitude of variation in sticking, the average relative discrepancy between the beam and theoretically derived sticking coefficients is 88%. The experimentally observed enhancement in dissociative sticking as beam translational energies decrease below approximately 10 kJ/mol is consistent with a parallel dynamical trapping/energy transfer channel that likely fails to completely thermalize the molecules to the surface temperature. This trapping-mediated sticking, indicative of specific energy transfer pathways from the surface under nonequilibrium conditions, should be a minor contributor to the overall dissociative sticking at thermal equilibrium. Surprisingly, the CH(4) dissociative sticking coefficient predicted for Ir(111) surfaces at thermal equilibrium, based on the molecular beam experiments, is roughly 4 orders of magnitude higher than recent measurements on supported nanoscale Ir catalysts at 1 bar pressure, which suggests that substantial improvements in catalyst turnover rates may be possible.
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Affiliation(s)
- Heather L Abbott
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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Kavulak DF, Abbott HL, Harrison I. Nonequilibrium Activated Dissociative Chemisorption: SiH4 on Si(100). J Phys Chem B 2004; 109:685-8. [PMID: 16866427 DOI: 10.1021/jp044841u] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A three-parameter local hot spot model of gas-surface reactivity is employed to analyze and predict dissociative sticking coefficients for SiH4 incident on Si(100) under varied nonequilibrium conditions. Two Si surface oscillators and the molecular vibrations, rotations, and translational energy directed along the local surface normal are active degrees of freedom in the 15 dimensional microcanonical kinetics. The threshold energy for SiH4 dissociative chemisorption is found to be 19 kJ/mol, in quantitative agreement with recent GGA-DFT calculations. A simple scheme for increasing the rate of chemical vapor deposition of silicon from SiH4 at low surface temperatures is modeled.
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Affiliation(s)
- David F Kavulak
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904-4319, USA
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