Monte Carlo simulations of surface reactions

Nieminen, R.M.; Jansen, Apj Tonek

doi:10.1016/s0926-860x(97)00130-0

Cited by 55 publications

(24 citation statements)

References 110 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The principal result of the paper is that the mean-field approximation, which is the standard ͑though often tacitly made͒ assumption in the electrochemical literature, breaks down severely if the adsorbed species which are involved in bimolecular surface reactions, do not diffuse. This result is well established in the statistical mechanics literature, 24 but it seems to be especially relevant to electrochemistry as many authors have invoked from their measurements that CO has a low mobility at the Pt/solution interface at room temperature. 9,10 This situation is in contrast with the CO oxidation on the Pt/gas interface, for which CO mobility is known to be high.…”

Section: Conclusion and Summarysupporting

confidence: 59%

“…On the theoretical side, it is of interest to develop approximations that go beyond the mean-field approximation and compare them to the MC results. 24 Also, the reaction model itself could be refined. One possibility is to treat more accurately the structural details of the CO adsorption, by allowing for adsorption on bridge and other multicoordinated sites, and including lateral interactions.…”

Section: Conclusion and Summarymentioning

confidence: 99%

See 1 more Smart Citation

Monte Carlo simulations of a simple model for the electrocatalytic CO oxidation on platinum

Koper

Jansen

Santen

et al. 1998

The Journal of Chemical Physics

195

253

View full text Add to dashboard Cite

A simple lattice-gas model for the electrocatalytic carbon monoxide oxidation on a platinum electrode is studied by dynamic Monte Carlo simulations. The CO oxidation takes place through a Langmuir-Hinshelwood reaction between adsorbed CO and an adsorbed OH radical resulting from the dissociative adsorption of water. The model enables the investigation of the role of CO surface mobility on the macroscopic electrochemical response such as linear sweep voltammetry and potential step chronoamperometry. Our results show that the mean-field approximation, the traditional but often tacitly made assumption in electrochemistry, breaks down severely in the limit of vanishing CO surface mobility. Comparison of the simulated and experimental voltammetry suggests that on platinum CO oxidation is the intrinsically fastest reaction on the surface and that CO has a high surface mobility. However, under the same conditions, the model predicts some interesting deviations from the potential step current transients derived from the classical nucleation and growth theories. Such deviations have not been reported experimentally. Furthermore, it is shown that our simple model predicts different Tafel slopes at low and high potential, the qualitative features of which are not strongly influenced by the CO mobility. The comparison of our simulation results to the experimental literature is discussed in some detail.

show abstract

Section: Conclusion and Summarysupporting

confidence: 59%

Section: Conclusion and Summarymentioning

confidence: 99%

Monte Carlo simulations of a simple model for the electrocatalytic CO oxidation on platinum

Koper

Jansen

Santen

et al. 1998

The Journal of Chemical Physics

195

253

View full text Add to dashboard Cite

show abstract

“…A simpler model with only one type of site, which was described previously, 20,21 was also considered. This model consists of a lattice of threefold sites; one site per metal atom, so either fcc or hcp.…”

Section: The Reaction Modelmentioning

confidence: 99%

“…We first performed simulations with the single-site model, 20,21 which was very well able to reproduce the TPD spectra, but, since it was only a single-site model, could not reproduce the correct spatial ordering of adsorbates on the surface. Adsorbates in this model occupy neighboring sites at higher coverages, i.e., sites one lattice vector apart.…”

Section: Single-site Modelmentioning

confidence: 99%

Combining density-functional calculations with kinetic models: NO/Rh(111)

Hermse

Frechard

Bavel

et al. 2003

The Journal of Chemical Physics

View full text Add to dashboard Cite

We present a dynamic Monte-Carlo model involving lateral interactions and different adsorption sites ͑top, fcc and hcp͒. Using this model in combination with kinetic parameters from UHV experiments and lateral interactions derived from DFT calculations we have reproduced the ordering behavior of NO on Rh͑111͒ during adsorption and the temperature programmed desorption ͑TPD͒ of NO from Rh͑111͒ under UHV conditions. The formation of c͑4ϫ2͒-2NO domains at 0.50 ML coverage is shown to depend strongly on the next-next-nearest-neighbor repulsion between the NO adsorbates in our model. The formation of the ͑2ϫ2͒-3NO structure at higher coverage follows from the avoidance of the strong next-nearest-neighbor repulsion in favor of the occupation of the top sites. A single-site model was able to reproduce the experimental TPD, but the lateral interactions were at odds with the values of the DFT calculations. A three-site model resolved this problem. It was found that all NO dissociates during TPD for initial coverages of NO below 0.20 ML. The nitrogen atoms recombine at higher temperatures. For NO coverages larger than 0.20 ML, 0.20 ML NO dissociates while the rest desorbs. This is due to a lack of accessible sites on the surface, i.e., sites where a molecule can bind without experiencing large repulsions with neighboring adsorbates. For NO coverages above 0.20 ML, the dissociation of NO causes a segregation into separate NO and NϩO islands. The dissociation causes the surface to be filled with adsorbates, and the adsorbates are therefore pushed closer together. NO on one hand can easily be compressed into islands of 0.50 ML coverage, because there is no large next-next-nearest-neighbor repulsion. NϩO on the other hand form islands with a lower coverage ͑0.30-0.35 ML͒ due to the considerable next-next-nearest-neighbor repulsion. Top bound NO ͑above 0.50 ML initial coverage͒ does not dissociate during TPD. It desorbs in a separate peak at 380 K.

show abstract

“…6,22,23 In contrast to these works, we present a multiscale analysis based on a realistic model for atomistic ordering and reaction kinetics for a specific reaction system, CO oxidation on Pd(100). Instead of the HCLG procedure, one could also analyze this system by scaling up simulations with lower CO hop rates (see Fig.…”

mentioning

confidence: 99%