Kinetic Prefactors of Reactions on Solid Surfaces
-
Charles T. Campbell
,
Líney Árnadóttir
Abstract
Adsorbed molecules are involved in many reactions on solid surfaces that are of great technological importance. As such, there has been tremendous effort worldwide to learn how to theoretically predict rates for reactions involving adsorbed molecules. Theoretical calculations of rate constants require knowing both their activation energy and prefactor. Recent advances in ab initio computational methods (e.g., density functional theory with periodic boundary conditions and van der Waals corrections) promise to soon provide activation energies for surface reactions with sufficient accuracy to have real predictive ability. However, to predict reaction rates, we also need accurate predictions of prefactors. We recently discovered that the standard entropies of adsorbed molecules (Sad0) linearly track the entropy of the gas-phase molecule at the same temperature (T), such that Sad0(T) = 0.70 Sgas0(T) − 3.3 R (R = the gas constant), with a standard deviation of only 2 R over a range of 50 R. This correlation, which applies only to conditions where their surface residence times are shorter than ∼ 1000 s, provides a powerful new method for estimating the partition functions for adsorbates and the kinetic prefactors for their reactions. For desorption, we show that the prefactors obtained with DFT using transition state theory (TST) and the harmonic oscillator approximation to get the partition function predicts prefactors for desorption that are of order 103 times larger than experimental values while our approach gives much better estimates. We also explore the applications of this approach to estimate prefactors within TST for the main classes of adsorbate reactions: desorption, diffusion, dissociation and association, and discuss its limitations. We discuss general issues associated with applying TST to rate laws and multi-step mechanisms in surface chemistry, and argue that rates of adsorbate reactions which are often taken to be proportional to coverage (θ) might better be taken as proportional to θ/(1 − θ) (unless the adsorbate forms islands), to account for the configurational entropy or excluded volume effects on the adsorbate's chemical potential.
© 2013 by Walter de Gruyter Berlin Boston
Artikel in diesem Heft
- Masthead
- Masthead
- Editorial
- Milestones in Physical Chemistry (I) – A Special Issue Honoring the Seminal Work of Henry Eyring and Michael Polanyi
- International Collaborations are nothing new... and sometimes they are simply amazing
- Personal Perspective
- A Comment on Henry Eyring
- Comment
- Michael Polanyi, the Scientist
- Historical Paper
- On Simple Gas Reactions
- Feature Article
- Probing Quantum Dynamics of Elementary Chemical Reactions via Accurate Potential Energy Surfaces
- Elementary Gas Phase Reactions
- Experimental and Theoretical Studies of Roaming Dynamics in the Unimolecular Dissociation of CH3NO2 to CH3O + NO
- Simultaneous Measurement of Reactive and Inelastic Scattering: Differential Cross Section of the H + HD → HD(v′, j′) + H Reaction
- The Decomposition of Hydrazine in the Gas Phase and over an Iridium Catalyst
- A Theoretical Study of the X-Abstraction Reactions (X = H, Br, or I) from CH2IBr by OH Radicals: Implications for Atmospheric Chemistry
- Models for Intrinsic Non-RRKM Dynamics. Decomposition of the SN2 Intermediate Cl––CH3Br
- Chemical Reactions at Surfaces
- Electronic Excitations in the Course of the Reaction of H with Coinage and Noble Metal Surfaces: A Comparison
- 7D Quantum Dynamics of H2 Scattering from Cu(111): The Accuracy of the Phonon Sudden Approximationy
- Exploring Pathways of Photoaddition Reactions by Artificial Force Induced Reaction Method: A Case Study on the Paternò–Büchi Reaction
- Kinetic Prefactors of Reactions on Solid Surfaces
- Electron-Transfer-Induced Dissociation of H2 on Gold Nanoparticles: Excited-State Potential Energy Surfaces via Embedded Correlated Wavefunction Theory
- Toward Detection of Electron-Hole Pair Excitation in H-atom Collisions with Au(111): Adiabatic Molecular Dynamics with a Semi-Empirical Full-Dimensional Potential Energy Surface
- Initial Sticking Coefficient of H2 on the Pd–Cu(111) Surface Alloy at very Low Coverages
- Catalyzed Surface-Aligned Reaction, H(ad) + H2(ad) = H2(g) + H(ad) on Coinage Metals
- Nitrogen Scattering at Ru(0001) Surfaces
- Ready, Set and no Action: A Static Perspective on Potential Energy Surfaces commonly used in Gas-Surface Dynamics
- Reactions in Clusters
- Potential Energy Surfaces and Rates of Spin Transitions
- A Full-Dimensional Neural Network Potential-Energy Surface for Water Clusters up to the Hexamer
- Embedded Cluster Models for Reactivity of the Hydrated Electron
- Novel Experimenta Methods
- Stark Deceleration of NO Radicals
- A Forty-Segment Molecular Synchrotron
Artikel in diesem Heft
- Masthead
- Masthead
- Editorial
- Milestones in Physical Chemistry (I) – A Special Issue Honoring the Seminal Work of Henry Eyring and Michael Polanyi
- International Collaborations are nothing new... and sometimes they are simply amazing
- Personal Perspective
- A Comment on Henry Eyring
- Comment
- Michael Polanyi, the Scientist
- Historical Paper
- On Simple Gas Reactions
- Feature Article
- Probing Quantum Dynamics of Elementary Chemical Reactions via Accurate Potential Energy Surfaces
- Elementary Gas Phase Reactions
- Experimental and Theoretical Studies of Roaming Dynamics in the Unimolecular Dissociation of CH3NO2 to CH3O + NO
- Simultaneous Measurement of Reactive and Inelastic Scattering: Differential Cross Section of the H + HD → HD(v′, j′) + H Reaction
- The Decomposition of Hydrazine in the Gas Phase and over an Iridium Catalyst
- A Theoretical Study of the X-Abstraction Reactions (X = H, Br, or I) from CH2IBr by OH Radicals: Implications for Atmospheric Chemistry
- Models for Intrinsic Non-RRKM Dynamics. Decomposition of the SN2 Intermediate Cl––CH3Br
- Chemical Reactions at Surfaces
- Electronic Excitations in the Course of the Reaction of H with Coinage and Noble Metal Surfaces: A Comparison
- 7D Quantum Dynamics of H2 Scattering from Cu(111): The Accuracy of the Phonon Sudden Approximationy
- Exploring Pathways of Photoaddition Reactions by Artificial Force Induced Reaction Method: A Case Study on the Paternò–Büchi Reaction
- Kinetic Prefactors of Reactions on Solid Surfaces
- Electron-Transfer-Induced Dissociation of H2 on Gold Nanoparticles: Excited-State Potential Energy Surfaces via Embedded Correlated Wavefunction Theory
- Toward Detection of Electron-Hole Pair Excitation in H-atom Collisions with Au(111): Adiabatic Molecular Dynamics with a Semi-Empirical Full-Dimensional Potential Energy Surface
- Initial Sticking Coefficient of H2 on the Pd–Cu(111) Surface Alloy at very Low Coverages
- Catalyzed Surface-Aligned Reaction, H(ad) + H2(ad) = H2(g) + H(ad) on Coinage Metals
- Nitrogen Scattering at Ru(0001) Surfaces
- Ready, Set and no Action: A Static Perspective on Potential Energy Surfaces commonly used in Gas-Surface Dynamics
- Reactions in Clusters
- Potential Energy Surfaces and Rates of Spin Transitions
- A Full-Dimensional Neural Network Potential-Energy Surface for Water Clusters up to the Hexamer
- Embedded Cluster Models for Reactivity of the Hydrated Electron
- Novel Experimenta Methods
- Stark Deceleration of NO Radicals
- A Forty-Segment Molecular Synchrotron
