The interaction of oxygen with a rhodium (110) surface

Schwarz, E.; Lenz, J.; Wohlgemuth, H.; Christmann, K.

doi:10.1016/0042-207x(90)90299-e

Cited by 71 publications

(37 citation statements)

References 15 publications

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“…TDS profiles possess several peaks and the intensities of the peaks oscillate with increasing oxygen exposure. For example, TDS from O-Pd [62] and O-Rh [173] surfaces show a similar number of peaks (4-5) with slight difference of peak temperatures. A correspondence needs to be identified between: (i) the TDS peaks and the bond strength and, (ii) the peak intensity oscillation and bond forming kinetics.…”

Section: Spectroscopes Correspondencesmentioning

confidence: 89%

“…LEED [173,176,179,181,182] and DFT [172,175] optimizations suggested that oxygen adsorbate prefers the hcp(0001)-facet site in the Rh(110)-(2Â1)p2mg-2O phase. Oxygen atom sits 0.5-0.6 Å above the top layer and bonds to one atom in the first layer and to two in the second.…”

Section: Xrd From O-cu(110)mentioning

confidence: 99%

“…30 shows the exposure-resolved TDS profiles recorded from the O-Rh(110) surface [173]. The TDS profiles exhibit five desorption maxima around 797, 835, 909, 1095 and 1150-1190 K. Besides the addition of the fifth peak, the peak temperatures for the O-Rh(110) surface are slightly higher than those for the O-Pd{(001), (110) By combining the TDS profiles and LEED crystallography of the O-Rh(110) surface, Schwarz et al [173] correlated the TDS peaks to the LEED patterns of various reconstructed phases. Comelli et al [27] re-interpreted the TDS data of the O-Rh(110) surface based on the known adsorbate's locations.…”

Section: Identity Similaritymentioning

confidence: 99%

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Oxidation electronics: bond–band–barrier correlation and its applications

Sun

2003

Progress in Materials Science

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Section: Spectroscopes Correspondencesmentioning

confidence: 89%

Section: Xrd From O-cu(110)mentioning

confidence: 99%

Section: Identity Similaritymentioning

confidence: 99%

See 1 more Smart Citation

Oxidation electronics: bond–band–barrier correlation and its applications

Sun

2003

Progress in Materials Science

215

167

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“…4. Note that oxygen is molecularly adsorbed in a precursor state before dissociating (24,25). Although the adsorption of oxygen is essentially irreversible in the temperature range of the experiment, the hydrogen adsorption is reversible because of its low desorption energy on rhodium.…”

Section: Reaction Schemementioning

confidence: 99%

Nanometric chemical clocks

McEwen

Gaspard

Bocarmé

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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Field ion microscopy combined with video techniques and chemical probing reveals the existence of catalytic oscillatory patterns at the nanoscale. This is the case when a rhodium nanosized crystalconditioned as a field emitter tip-is exposed to hydrogen and oxygen. Here, we show that these nonequilibrium oscillatory patterns find their origin in the different catalytic properties of all of the nanofacets that are simultaneously exposed at the tip's surface. These results suggest that the underlying surface anisotropy, rather than a standard reaction-diffusion mechanism, plays a major role in determining the self-organizational behavior of multifaceted nanostructured surfaces. Surprisingly, this nanoreactor, composed of the tip crystal and a constant molecular flow of reactants, is large enough for the emergence of regular oscillations from the molecular fluctuations.field ion microscopy ͉ heterogeneous catalysis ͉ nanopatterns ͉ nonequilibrium oscillations T he Belousov-Zhabotinskii reaction is probably the most famous example of an oscillating chemical reaction in the liquid phase (1, 2). However, studies of oscillations in heterogeneous catalysis begun in the 1970s (3, 4). One decade later, Ertl et al. demonstrated for the first time (5, 6) that oscillatory surface reactions are associated with the occurrence of specific pattern formations ranging from tens to hundreds of micrometers. More recently, oscillations have been discovered on the nanoscale in field electron and field ion microscopes by using video techniques (FEM and FIM, respectively) (7-10). At this length scale of tens of nanometers, self-sustained oscillatory patterns are observed about which little is known. This is certainly the case for the catalytic water production when exposing oxygen and hydrogen to a rhodium field emitter tip (11,12). Our purpose in the present article is to show that this nonequilibrium self-organizational behavior can be understood by taking into account the structural anisotropy of the crystalline tip that results in different catalytic properties on the various nanofacets. Moreover, we demonstrate that the external electric field, as applied in a FIM (of the order of 10 V/nm), promotes surface oxidation thus giving way to a feedback mechanism to explain self-sustained rate oscillations in the H 2 /O 2 /Rh system.The understanding of self-sustained oscillations at the macroscale was pioneered by Prigogine who showed that such phenomena are consistent with thermodynamics as long as the system is open and far from equilibrium (13). Such selforganization phenomena are understood in terms of reactiondiffusion processes, which also explains the mesoscopic patterns observed on oriented metal single-crystal surfaces (14, 15). However, the nanopatterns observed during a catalytic reaction in a FIM have a spatial scale smaller than typical diffusion lengths. Moreover, one may wonder how the molecular fluctuations that manifest themselves in such small systems (16, 17) affect the oscillations. Indeed, their regularity disappears...

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“…STM work shows that the oxygen atoms form zigzag rows in the trough. [34][35][36] These oxygen atoms can be removed by hydrogen or CO so that the surface can remain in a ͑1 ϫ 2͒ or ͑1 ϫ n͒ missing-row configuration. 37 This structure is metastable and can be converted back into a ͑1 ϫ 1͒ form above about 480 K. Therefore, the ͑1 ϫ 1͒ LEED pattern under reducing conditions is reasonable.…”

Section: A Surface Structuresmentioning

confidence: 99%

The collimation angle shift of desorbing product N2 in a steady-state N2O+CO reaction on Rh(110)

Matsushima

Nakagoe

Shobatake

et al. 2006

The Journal of Chemical Physics

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The angular distribution of desorbing product N 2 was studied in N 2 O decompositions on Rh͑110͒ in the temperature range of 60-700 K. The N 2 desorption collimates along 62°-68°off normal toward either the ͓001͔ or ͓001͔ direction in a transient N 2 O decomposition below ca. 470 K or in the steady-state N 2 O + CO reaction above 540 K. In the steady-state reaction at the temperature from ca. 470 to 540 K, however, the collimation angle shifts from 62°to 45°with decreasing surface temperature. This angle shift is ascribed to the steric hindrance by coadsorbed CO because the N 2 collimation in transient N 2 O decomposition at around 65°is recovered in the range of 380-500 K by an abrupt CO pressure drop followed by the decrease in CO coverage. N 2 O is oriented along the ͓001͔ direction before dissociation. A scattering model of the nascent N 2 by adsorbed CO is proposed, yielding smaller collimation angles.

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The interaction of oxygen with a rhodium (110) surface

Cited by 71 publications

References 15 publications

Oxidation electronics: bond–band–barrier correlation and its applications

Oxidation electronics: bond–band–barrier correlation and its applications

Nanometric chemical clocks

The collimation angle shift of desorbing product N2 in a steady-state N2O+CO reaction on Rh(110)

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