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Mechanism of CO Oxidation on Cu 2 O (111) Surface: A DFT and Microkinetic Study
Author(s) -
Wu LingNan,
Tian ZhenYu,
Qin Wu
Publication year - 2018
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.21176
Subject(s) - chemistry , adsorption , density functional theory , catalysis , reaction mechanism , redox , transition state , transition state theory , reaction rate constant , activation energy , catalytic cycle , molecule , photochemistry , computational chemistry , inorganic chemistry , kinetics , organic chemistry , physics , quantum mechanics
ABSTRACT Catalytic oxidation has been recognized as one of the most efficient and promising techniques for the abatement of CO and volatile organic compounds. In the present work, the CO oxidation mechanism on perfect Cu 2 O (111) surface was investigated by using density functional theory (DFT) calculations with the periodic surface model. The unsaturated singly coordinated Cu + site of Cu 2 O (111) surface could effectively adsorb gaseous CO molecule with a strong adsorption energy of −1.558 eV. The adsorbed O on Cu 2 O (111) surface is very active toward CO oxidation with only 0.269 eV energy barrier. The reaction between CO and lattice O is the rate‐determining step of Mars‐van‐Krevelen (MvK) type CO oxidation with the energy barrier of 1.629 eV. The CO oxidation cycle initiated by the reaction between coadsorbed CO and O 2 at the Cu I site has a relatively lower energy barrier of 1.082 eV and is, therefore, more likely to proceed compared with the MvK cycle. Microkinetic rate constants of elementary reaction steps based on the transition state theory were deduced, which could be helpful in the kinetic modeling of CO oxidation on Cu 2 O surface.