Reaction diffusion patterns in the catalytic CO-oxidation on Pt(110): Front propagation and spiral waves

Nettesheim, Stefan; Oertzen, Alexander von; Rotermund, Harm Hinrich; Ertl, G.

doi:10.1063/1.464323

Cited by 274 publications

(174 citation statements)

References 30 publications

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“…Electronic mail: tatmatsu@cat.hokudai.ac.jp adsorption to O 2 dissociation, i.e., the surface species change from CO(a)ϽO(a) to CO(a)ϾO(a). Especially, when the critical pressure is high enough to be close to the oscillation conditions, CO͑a͒ and O͑a͒ form separate domains with peculiar patterns, 11,12 and those domains move on the surface, as observed in PEEM images. CO͑a͒ domains stabilize the ͑1ϫ1͒ form, and O͑a͒ domains are on the ͑1ϫ2͒ form.…”

Section: Introductionmentioning

confidence: 89%

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CO 2 desorption dynamics on specified sites and surface phase transitions of Pt(110) in steady-state CO oxidation

Rzeznicka

Moula

Garza

et al. 2003

The Journal of Chemical Physics

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The spatial and velocity distributions of desorbing product CO 2 were studied in the steady-state CO oxidation on Pt͑110͒ by cross-correlation time-of-flight techniques. The surface structure transformation was monitored by LEED in the course of the catalyzed reaction. In the active region, where the surface was highly reconstructed into the missing-row form, CO 2 desorption split into two directional lobes collimated along 25°from the surface normal in the plane including the ͓001͔ direction, indicating the CO 2 formation on inclined ͑111͒ terraces. The translational temperature was maximized at the collimation angle, reaching about 1900 K. On the other hand, CO 2 desorption sharply collimated along the surface normal at CO pressures where ͑1ϫ2͒ domains disappeared. The distribution change from an inclined desorption to a normally directed one was abrupt at the CO pressure where the half-order LEED spot already disappeared. This switching point was more sensitive than LEED towards the complete transformation from ͑1ϫ2͒ to ͑1ϫ1͒ and was then used to construct a surface phase diagram for working reaction sites in the pressure range from 1ϫ10 Ϫ7 Torr to 1ϫ10 Ϫ4 Torr of oxygen. The turnover frequency of CO 2 formation was enhanced on ͑1ϫ2͒ domains with increasing CO pressure.

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Section: Introductionmentioning

confidence: 89%

“…This distribution continued in the boundary region. It was approximated as cos 11 (ϩ25)ϩcos 11 ( Ϫ25). In the highly inhibited region, the observed distribution became the normally directed form of an approximate cos 3 form.…”

Section: B Angular Distributionmentioning

confidence: 99%

CO 2 desorption dynamics on specified sites and surface phase transitions of Pt(110) in steady-state CO oxidation

Rzeznicka

Moula

Garza

et al. 2003

The Journal of Chemical Physics

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“…Both the adsorbed layer kinetics and the nature of the surface reconstruction can be modified from that considered here. In particular, detailed studies of pattern formation at the mesoscopic level [24,25] should be possible using such a model and the influence of fluctuations and the possible breakdown of deterministic descriptions can be considered. = 0.015 and δ = 10.…”

Section: Discussionmentioning

confidence: 99%

Surface structure and catalytic CO oxidation oscillations

Danielak

Perera²,

Moreau³

et al. 1996

Physica A: Statistical Mechanics and its Applications

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A cellular automaton model is used to describe the dynamics of the catalytic oxidation of CO on a P t(100) surface. The cellular automaton rules account for the structural phase transformations of the P t substrate, the reaction kinetics of the adsorbed phase and diffusion of adsorbed species. The model is used to explore the spatial structure that underlies the global oscillations observed in some parameter regimes. The spatiotemporal dynamics varies significantly within the oscillatory regime and depends on the harmonic or relaxational character of the global oscillations. Diffusion of adsorbed CO plays an important role in the synchronization of the patterns on the substrate and this effect is also studied.

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“…The surface orientation has a decisive effect on pattern formation: in the [111] orientation there is no phase change and hence no patterns, on Pt{110} classical spirals and targets are seen (e.g. [3]), while on Pt{100} the patterns are typically more irregular [4][5][6], though circular wavefronts are also seen [5].…”

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confidence: 99%

Pattern Formation during the Oxidation of CO onPt{100}: A Mesoscopic Model

et al. 2007

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Constantly changing irregular patterns of carbon monoxide (CO) and oxygen are seen during CO oxidation on platinum crystals in the [100] orientation. Ours is the first reaction-diffusion model to reproduce this pattern formation on physically feasible length and time scales, faithfully incorporating the available experimental data. Numerical simulations show patterns made up of CO and oxygen fronts moving at similar speeds to those seen in experiments [4][5][6].PACS numbers: 68.43. Bc,68.47.De,82.40.Ck Spatiotemporal pattern formation occurs in a number of catalytic reactions, such as the Belousov-Zhabotinsky reaction where oscillating spirals and targets are seen [1]. Similar structures form during the catalytic oxidation of carbon monoxide on the surface of single platinum crystals, where patterns comprise areas of different surface phase or covered by different adsorbates. During the reaction oxygen and CO are adsorbed onto the platinum surface. At high enough temperatures and for certain orientations of the surface relative to the bulk crystal, the presence of adsorbates leads to a phase change, i.e. a rearrangement of the surface platinum atoms. When the oxygen and CO react, carbon dioxide gas is released and the surface reverts to its original configuration. This cycle can lead to kinetic oscillations in the surface phase. If communication between different areas on the crystal is very rapid compared with the rate of oscillation, the whole surface oscillates in phase; otherwise there can be phase lags across the surface and spatial patterns arise [2]. There are two main spatial coupling mechanisms: diffusion of CO across the surface, important at low pressures, and global coupling through the gas phase, which dominates at high pressures. The surface orientation has a decisive effect on pattern formation: in the [111] orientation there is no phase change and hence no patterns, on Pt{110} classical spirals and targets are seen (e.g. [3]), while on Pt{100} the patterns are typically more irregular [4-6], though circular wavefronts are also seen [5].In this Letter, we model pattern formation in CO oxidation on a single platinum crystal in the [100] orientation. The kinetic mechanism for this reaction is well established and has been modelled extensively [7][8][9]. Spatial modelling has concentrated on Pt{110} using a simplified representation of the kinetic mechanism, extended to include diffusion terms (and sometimes gas global coupling) [10]. These models produce results that qualitatively resemble experimentally observed patterns, but they cannot be used for detailed quantitative comparison since both the kinetic and diffusion mechanisms are simplified. Monte Carlo methods are also used, but at present these must assume unrealistically low diffusion coefficients in order to allow pattern formation on computationally accessible length and time scales [11]. We present a mesoscopic spatial model based on the detailed kinetic mechanism [9] together with diffusion terms derived from a careful consideration of...

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Reaction diffusion patterns in the catalytic CO-oxidation on Pt(110): Front propagation and spiral waves

Cited by 274 publications

References 30 publications

CO 2 desorption dynamics on specified sites and surface phase transitions of Pt(110) in steady-state CO oxidation

CO 2 desorption dynamics on specified sites and surface phase transitions of Pt(110) in steady-state CO oxidation

Surface structure and catalytic CO oxidation oscillations

Pattern Formation during the Oxidation of CO onPt{100}: A Mesoscopic Model

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