Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Effect of Frustrated Rotations on the Pre-Exponential Factor for Unimolecular Reactions on Surfaces: A Case Study of Alkoxy Dehydrogenation

Journal Article · · Journal of Physical Chemistry. C
 [1];  [2];  [2];  [2];  [2];  [3];  [2]
  1. Harvard Univ., Cambridge, MA (United States); Harvard University
  2. Harvard Univ., Cambridge, MA (United States)
  3. Univ. of California, Los Angeles, CA (United States)
+ Show Author Affiliations
If theory is to be able to predict the rates of catalytic reactions over extended ranges of temperature and pressure, it must provide accurate rate constants for elementary reaction steps, including both the activation energy and pre-exponential factor. A standing difficulty with this objective is the treatment of floppy modes in the partition function for the adsorbed species. This issue leads to limited accuracy in the pre-exponential factor computed for realistic systems. Here we investigate the C–H bond breaking for a series of linear-chain alkoxides on Cu(110) using density functional theory, since the results can be compared to experimental data for the rate constants. The structural similarity of these species enables us to understand the systematic effect of molecular size on the frustrated motions and pre-exponential factor. First, we discuss the complexities of finding the global minimum structure of the adsorbed species and highlight the high dimensionality of configuration space to be sampled. Then, we analyze the motions of harmonic normal modes, including the motions of the underlying metal atoms, and compute the harmonic pre-exponential factors. To account for periodic frustrated rotations we use the hindered rotor model: this motion significantly decreases the pre-exponential factor in the C–H bond breaking, the effect increasing with molecular size. We also estimate the anharmonic effect using the Morse treatment of potentials. The activation energy and pre-exponential factor computed for CH3O are in excellent quantitative agreement with experiment. Finally, the trends computed for the homologous series of alcohols are also reflected by experiment.
Research Organization:
Energy Frontier Research Centers (EFRC) (United States). Integrated Mesoscale Architectures for Sustainable Catalysis (IMASC); Harvard Univ., Cambridge, MA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
SC0012573
OSTI ID:
1595062
Journal Information:
Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 2 Vol. 124; ISSN 1932-7447
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (35)

Using microkinetic analysis to search for novel anhydrous formaldehyde production catalysts journal November 2015
Quantum Chemical Free Energies: Structure Optimization and Vibrational Frequencies in Normal Modes journal October 2013
Long time scale kinetic Monte Carlo simulations without lattice approximation and predefined event table journal December 2001
The Activated Complex in Chemical Reactions journal February 1935
Kinetic Prefactors of Reactions on Solid Surfaces journal January 2013
Replication Data for: Dissecting the Performance of Nanoporous Gold Catalysts for Oxygen-Assisted Coupling of Methanol with Fundamental Mechanistic and Kinetic Information dataset January 2019
First-Principles Kinetic Monte Carlo Simulations for Heterogeneous Catalysis: Concepts, Status, and Frontiers book November 2011
Ab Initio Calculation of Rate Constants for Molecule-Surface Reactions with Chemical Accuracy journal March 2016
The Renewable Chemicals Industry journal April 2008
Metadynamics: Metadynamics
  • Barducci, Alessandro; Bonomi, Massimiliano; Parrinello, Michele
  • Wiley Interdisciplinary Reviews: Computational Molecular Science, Vol. 1, Issue 5 https://doi.org/10.1002/wcms.31
journal February 2011
Nonphysical sampling distributions in Monte Carlo free-energy estimation: Umbrella sampling journal February 1977
Primary and secondary kinetic isotope effects for methoxy dehydrogenation and Cu(110): Absence of tunnelling corrections journal May 1995
One-dimensional anharmonic oscillator: Quantum versus classical vibrational partition functions journal June 2010
Heterogeneous Catalysis: A Central Science for a Sustainable Future journal March 2017
General Effect of van der Waals Interactions on the Stability of Alkoxy Intermediates on Metal Surfaces journal August 2017
Hindered Translator and Hindered Rotor Models for Adsorbates: Partition Functions and Entropies journal April 2016
Equilibrium Constants and Rate Constants for Adsorbates: Two-Dimensional (2D) Ideal Gas, 2D Ideal Lattice Gas, and Ideal Hindered Translator Models journal May 2016
Density Functional Theory (DFT) and Kinetic Monte Carlo (KMC) Study of the Reaction Mechanism of Hydrogen Production from Methanol on ZnCu(111) journal November 2016
First-Principles Study of Alkoxides Adsorbed on Au(111) and Au(110) Surfaces: Assessing the Roles of Noncovalent Interactions and Molecular Structures in Catalysis journal December 2017
A Comparative Ab Initio Study of Anhydrous Dehydrogenation of Linear-Chain Alcohols on Cu(110) journal March 2018
Enhancing the Hydrogen Activation Reactivity of Nonprecious Metal Substrates via Confined Catalysis Underneath Graphene journal September 2016
Dissecting the Performance of Nanoporous Gold Catalysts for Oxygen-Assisted Coupling of Methanol with Fundamental Mechanistic and Kinetic Information journal April 2019
Effect of Anharmonicity on Adsorption Thermodynamics journal May 2014
Noncovalent Bonding Controls Selectivity in Heterogeneous Catalysis: Coupling Reactions on Gold journal November 2016
Towards tomorrow's catalysts journal November 2004
Towards the computational design of solid catalysts journal April 2009
Self-assembly of acetate adsorbates drives atomic rearrangement on the Au(110) surface journal October 2016
The path towards sustainable energy journal December 2016
Crossing the great divide between single-crystal reactivity and actual catalyst selectivity with pressure transients journal November 2018
First-principles kinetic modeling in heterogeneous catalysis: an industrial perspective on best-practice, gaps and needs journal January 2012
Identifying key descriptors in surface binding: interplay of surface anchoring and intermolecular interactions for carboxylates on Au(110) journal January 2018
A climbing image nudged elastic band method for finding saddle points and minimum energy paths journal December 2000
A dimer method for finding saddle points on high dimensional potential surfaces using only first derivatives journal October 1999
VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data journal October 2011
Kinetic Prefactors of Reactions on Solid Surfaces journal January 2013

Similar Records

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY