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Title: A master equation simulation for the OH + CH 3 OH reaction

Journal Article · · Journal of Chemical Physics
DOI: https://doi.org/10.1063/1.5081827 · OSTI ID:1503282

A combined (fixed-J) two-dimensional master-equation / semi-classical transition state theory / variational Rice-Ramsperger-Kassel-Marcus (2DME/SCTST/vRRKM) approach has been used to compute reaction rate coefficients of •OH with CH3OH over a wide range of temperatures (10 - 2500 K) and pressures (10-1-104 Torr) based on a potential energy surface that has been constructed using a modification of the HEAT thermochemical protocol. The calculated results show that the title reaction is nearly pressure-independent when T > 250 K, but depends strongly on pressure at lower temperatures. Also, the preferred mechanism and rate constants are found to be very sensitive to temperature. The reaction pathway CH3OH + OH → CH3O + H2O proceeds exclusively through tunneling at exceedingly low temperatures (T ≤50 K) typical of those established in interstellar environments. In this regime, the rate constant is found to increase with decreasing temperature, which agrees with low-temperature experimental results. The thermodynamically favored reaction pathway CH3OH + OH → CH2OH + H2O becomes dominant at higher temperatures (T ≥ 200 K), such as those found in Earth’s atmosphere as well as combustion environments. By modifying the ab initio barrier heights slightly, experimental rate constants from 200 to 1250 K can be satisfactorily reproduced.

Research Organization:
Argonne National Laboratory (ANL), Lemont, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
Grant/Contract Number:
AC02-06CH11357; FG02-07ER15884
OSTI ID:
1503282
Journal Information:
Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 8 Vol. 150; ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English

References (62)

Application of inverse iteration to 2‐dimensional master equations journal June 1997
Rate Constants and CH3O Product Yield of the Reaction OH + CH3OH → Products journal November 1983
Methanol oxidation in a flow reactor: Implications for the branching ratio of the CH3OH+OH reaction journal January 2008
The gas phase reactions of hydroxyl radicals with a series of aliphatic alcohols over the temperature range 240-440 K journal November 1987
Kinetics of the reaction of OH radicals with CH3OH and CD3OD studied by laser photolysis coupled to high repetition rate laser induced fluorescence journal April 2009
Temperature dependence and branching ratio of the CH3OH + OH reaction journal April 1984
Non-iterative fifth-order triple and quadruple excitation energy corrections in correlated methods journal February 1990
Semiclassical transition state theory. A new perspective journal October 1993
Vibration–Rotation Structure in Asymmetric- and Symmetric-Top Molecules book January 1972
A practical implementation of semi-classical transition state theory for polyatomics journal October 2010
Theoretical study on the kinetics for OH reactions with CH3OH and C2H5OH journal January 2007
A shock tube study of CH 3 OH + OH → Products using OH laser absorption journal January 2015
A fifth-order perturbation comparison of electron correlation theories journal May 1989
Kinetics of the reactions of the hydroxyl radical with CH3OH and C2H5OH between 235 and 360 K journal May 2003
A Steady-State Approximation to the Two-Dimensional Master Equation for Chemical Kinetics Calculations journal February 2015
Active Thermochemical Tables: Sequential Bond Dissociation Enthalpies of Methane, Ethane, and Methanol and the Related Thermochemistry journal February 2015
Stabilization of the Simplest Criegee Intermediate from the Reaction between Ozone and Ethylene: A High-Level Quantum Chemical and Kinetic Analysis of Ozonolysis journal May 2015
Three-Dimensional Master Equation (3DME) Approach journal August 2018
Semiclassical Transition-State Theory Based on Fourth-Order Vibrational Perturbation Theory: The Symmetrical Eckart Barrier journal June 2016
Unimolecular Reaction of Methyl Isocyanide to Acetonitrile: A High-Level Theoretical Study journal April 2018
Variational unimolecular rate theory journal July 1983
Current status of transition-state theory journal July 1983
Kinetic studies of the reactions of atomic fluorine and hydroxyl radical with methanol journal February 1989
Hydrogen-atom abstraction from methanol by hydroxyl radical journal March 1989
Current status of transition-state theory journal December 1983
Kinetics of the Methanol Reaction with OH at Interstellar, Atmospheric, and Combustion Temperatures journal February 2018
Solution of Some One- and Two-Dimensional Master Equation Models for Thermal Dissociation:  The Dissociation of Methane in the Low-Pressure Limit journal May 2002
Introduction to Active Thermochemical Tables:  Several “Key” Enthalpies of Formation Revisited journal November 2004
Ab Initio Reaction Rate Constants Computed Using Semiclassical Transition-State Theory: HO + H 2 → H 2 O + H and Isotopologues journal May 2011
Theoretical Study of Reaction of Ketene with Water in the Gas Phase: Formation of Acetic Acid? journal October 2013
Low Temperature Kinetics of the CH 3 OH + OH Reaction journal April 2014
13 C, 18 O, and D Fractionation Effects in the Reactions of CH 3 OH Isotopologues with Cl and OH Radicals journal November 2008
Full Iterative Solution of the Two-Dimensional Master Equation for Thermal Unimolecular Reactions journal January 1996
Current Status of Transition-State Theory journal January 1996
Theoretical Study of the Kinetics of the Hydrogen Abstraction from Methanol. 3. Reaction of Methanol with Hydrogen Atom, Methyl, and Hydroxyl Radicals journal May 1999
Reaction of HO with CO: Tunneling Is Indeed Important journal May 2012
Accelerated chemistry in the reaction between the hydroxyl radical and methanol at interstellar temperatures facilitated by tunnelling journal June 2013
Gas phase reactions of C 1 –C 4 alcohols with the OH radical: A quantum mechanical approach journal January 2002
Kinetics of the reactions of HO with methanol (210–351 K) and with ethanol (216–368 K) journal January 2005
Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature journal January 2016
Comment on “Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature” by W. Siebrand, Z. Smedarchina, E. Martínez-Núñez and A. Fernández-Ramos, Phys. Chem. Chem. Phys ., 2016, 18 , 22712 journal January 2018
Reply to the ‘Comment on “Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature”’ by D. Heard, R. Shannon, J. Gomez Martin, R. Caravan, M. Blitz, J. Plane, M. Antiñolo, M. Agundez, E. Jimenez, B. Ballesteros, A. Canosa, G. El Dib, J. Albaladejo and J. Cernicharo, Phys. Chem. Chem. Phys. , 2018, 20 , DOI: 10.1039/C7CP04561A journal January 2018
Semi-classical theory for non-separable systems:. Construction of “good” action-angle variables for reaction rate constants journal January 1977
Evaluated Kinetic Data for Combustion Modeling: Supplement II journal September 2005
HEAT: High accuracy extrapolated ab initio thermochemistry journal December 2004
High-accuracy extrapolated ab initio thermochemistry. II. Minor improvements to the protocol and a vital simplification journal August 2006
High-accuracy extrapolated ab initio thermochemistry. III. Additional improvements and overview journal March 2008
Unified statistical model for ’’complex’’ and ’’direct’’ reaction mechanisms journal September 1976
General contraction of Gaussian basis sets. I. Atomic natural orbitals for first‐ and second‐row atoms journal April 1987
General contraction of Gaussian basis sets. II. Atomic natural orbitals and the calculation of atomic and molecular properties journal January 1990
Master equation analysis of intermolecular energy transfer in multiple-well, multiple-channel unimolecular reactions. II. Numerical methods and application to the mechanism of the C2H5+O2 reaction journal November 1999
Communication: Thermal unimolecular decomposition of syn-CH 3 CHOO: A kinetic study journal October 2016
The Rate-Constant of the Reaction of Hydroxyl Radicals With Methanol, Ethanol and (D3)Methanol journal January 1986
The importance of OH radical–neutral low temperature tunnelling reactions in interstellar clouds using a new model journal May 2014
Quantum dynamics of complex-forming bimolecular reactions journal January 2012
Active Thermochemical Tables: thermochemistry for the 21st century journal January 2005
On the Quantum Mechanics of the Rotational Distortion of Multiplets in Molecular Spectra journal August 1928
Methylhydroxycarbene: Tunneling Control of a Chemical Reaction journal June 2011
Predictive a priori pressure-dependent kinetics journal December 2014
Variational Transition State Theory journal October 1984
REACTIVITY OF OH AND CH 3 OH BETWEEN 22 AND 64 K: MODELING THE GAS PHASE PRODUCTION OF CH 3 O IN BARNARD 1b journal May 2016
Reactivity of OH and CH3OH between 22 and 64 K: Modelling the gas phase production of CH3O in Barnard 1b text January 2016

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Gas-phase reactivity of CH 3 OH toward OH at interstellar temperatures (11.7–177.5 K): experimental and theoretical study journal January 2019
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