TY - JOUR
T1 - Quantum chemical study of the dissociative adsorption of OH and H 2O on pristine and defective graphite (0001) surfaces
T2 - Reaction mechanisms and kinetics
AU - Xu, S. C.
AU - Irle, S.
AU - Musaev, D. G.
AU - Lin, Ming-Chang
PY - 2007/1/25
Y1 - 2007/1/25
N2 - Quantum chemical studies of the dissociative adsorption mechanisms and kinetics of OHx (x = 1, 2) on graphite (0001) surface models were carried out with emphasis on the influence of surface defects. Finite-size model systems for Stone-Wales type (SW), mono- (1V), and divacancy (2V) defects are studied in addition to the defect-free (0D) surface models. Horizontal and vertical bulk effects have been considered by variation of the model system size and number of graphene layers. Potential energy surfaces for dissocative adsorption of one and two OH radicals on pristine graphite and for H 2O adsorption on 1V, 2V, and SW defects are presented at the dispersion-augmented density functional tight binding (DFTB-D), integrated ONIOM(B3LYP/6-31+G(d):DFTB-D), and density functional theory B3LYP/6-31+G(d) levels of theory. OH is found to oxidatively erode the graphite surface by producing gaseous CO and hydrogenated vacancy defects (L1H1V), while water is found to react only with monovacancy defects. The rate constants for the dissociative adsorption have been predicted by RRKM theory. Quantum chemical molecular dynamical (QM/MD) simulations at high temperatures of adsorption products of OH and H2O on graphite surface models have been carried out using the DFTB-D method.
AB - Quantum chemical studies of the dissociative adsorption mechanisms and kinetics of OHx (x = 1, 2) on graphite (0001) surface models were carried out with emphasis on the influence of surface defects. Finite-size model systems for Stone-Wales type (SW), mono- (1V), and divacancy (2V) defects are studied in addition to the defect-free (0D) surface models. Horizontal and vertical bulk effects have been considered by variation of the model system size and number of graphene layers. Potential energy surfaces for dissocative adsorption of one and two OH radicals on pristine graphite and for H 2O adsorption on 1V, 2V, and SW defects are presented at the dispersion-augmented density functional tight binding (DFTB-D), integrated ONIOM(B3LYP/6-31+G(d):DFTB-D), and density functional theory B3LYP/6-31+G(d) levels of theory. OH is found to oxidatively erode the graphite surface by producing gaseous CO and hydrogenated vacancy defects (L1H1V), while water is found to react only with monovacancy defects. The rate constants for the dissociative adsorption have been predicted by RRKM theory. Quantum chemical molecular dynamical (QM/MD) simulations at high temperatures of adsorption products of OH and H2O on graphite surface models have been carried out using the DFTB-D method.
UR - http://www.scopus.com/inward/record.url?scp=33847345075&partnerID=8YFLogxK
U2 - 10.1021/jp066142i
DO - 10.1021/jp066142i
M3 - Article
AN - SCOPUS:33847345075
SN - 1932-7447
VL - 111
SP - 1355
EP - 1365
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 3
ER -