Chemisorption geometry of NO on Rh(111) by X-ray photoelectron diffraction

Kim, Y.J; Thevuthasan, S.; Herman, Gregory S.; Peden, Charles H. F.; Chambers, Scott A.; Belton, David N.; Permana, H.

doi:10.1016/0039-6028(96)00027-1

Cited by 71 publications

(52 citation statements)

References 40 publications

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“…Previously the p͑2 ϫ 2͒-3NO structure was obtained from high-resolution electron-energy-loss spectroscopy and low-energy electron diffraction data. [39][40][41] It was also determined from DFT calculation by Loffreda et al 7 and more recently by Vang et al 12 According to the experimental data and the first calculations 7 the most stable configuration consists of ͑top+ fcc+ hcp͒ NO with all NO's in the up-right position ͑Fig. 3͒.…”

Section: B P"2 ã 2…-3no and P"3 ã 3…-7nomentioning

confidence: 99%

NO structures adsorbed on Rh(111): Theoretical approach to high-coverage STM images

et al. 2006

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Theoretical modeling of scanning tunneling microscopy ͑STM͒ measurements is used for the interpretation of images of nitrogen monoxide on Rh͑111͒ surfaces in order to gain insight into the factors which control the contrast of an STM image, especially in the case of high coverage overlayers. Topographic images of NO/Rh͑111͒ for different coverages and adsorption positions were calculated. These results were used to analyze the experimental images obtained for the p͑2 ϫ 2͒-3NO and p͑3 ϫ 3͒-7NO high coverage structures. The theoretical calculations confirm that not all NO molecules present on the surface can be observed experimentally, the image being dominated by the contribution of top NO molecules in the adlayer. In addition, the calculations reveal that destructive interference effects between molecular contributions in the tunnel current play a decisive role for the different contrast of the two high coverage structures. A general discussion of why and how the differences in the adsorbate surface configuration reflect the experimental STM images is given.

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Section: B P"2 ã 2…-3no and P"3 ã 3…-7nomentioning

confidence: 99%

NO structures adsorbed on Rh(111): Theoretical approach to high-coverage STM images

et al. 2006

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“…The reason for not including the bridge site stems from the observation by means of XPS 16 and EELS 1,17 that NO on Rh͑111͒ occupies only two kinds of sites, which were later identified as top and threefold. 2,18 Probably the bridge sites do not allow for a favorable distribution of adsorbates avoiding lateral interactions, and are therefore not significantly occupied.…”

Section: The Reaction Modelmentioning

confidence: 99%

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

Hermse

Frechard

Bavel

et al. 2003

The Journal of Chemical Physics

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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.

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“…An increase in the peak intensity and a peak shift to higher frequency were seen as the NO exposure was increased to 4 L, at which point the peak had shifted to 1,606 cm -1 . At exposures above 5 L, the peak intensity gradually decreased with increasing NO exposure; and at 5 L, a new peak appeared at 1,813 cm -1 , and the peak increased in intensity with increasing NO exposure up to 12-16 L. A third peak was observed at 1,495 cm -1 above 16 L. The intensities of the three NO adsorption peaks at 1,495, 1,606, and 1,813 cm -1 became constant above 48 L. From the literature data [16,49], the peaks at 1495, 1606, and 1,813 cm -1 were assigned to NO adsorbed on hcp, fcc, and atop sites, respectively. In the NO adsorption process, the fcc-NO peak shifted continuously from 1,477 to 1,606 cm -1 with increasing NO exposure between 0.2 and 4 L; note that the peak shift is due to a change in the intermolecular interactions that accompany the increased NO coverage.…”

Section: Adsorption and Decomposition Of No On Rh(111)mentioning

confidence: 77%

“…For the NO reactivity on the Rh single crystal, the adsorption, dissociation and desorption properties have been extensively examined using various crystal planes such as (111) [11][12][13][14][15][16], (100) [17][18][19][20][21], (110) [22][23][24][25][26], and stepped [19,[27][28][29] surfaces. The adsorbed NO on the Rh surface dissociates completely upon heating at low NO coverage, whereas the dissociation percentage decreases with increasing NO coverage.…”

Section: Introductionmentioning

confidence: 99%

Adsorption Behavior and Reaction Properties of NO and CO on Ir(111) and Rh(111)

Nakamura

Fujitani

2009

Catal Surv Asia

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Adsorption and reactions of NO over the clean and and Rh(111) surfaces were investigated using infrared reflection absorption spectroscopy (IRAS) and temperature programmed desorption (TPD). Two NO adsorption states, indicative of hollow and atop sites, were present on Ir(111). Only NO adsorbed on hollow sites dissociated to N a and O a . The dissociated N a desorbed as N 2 by recombination of N a and by a disproportionation reaction between atop-NO and N a . Preadsorbed CO inhibited atop-NO, whereas hollow-NO was not affected. Adsorbed CO reacted with O a and desorbed as CO 2 . NO adsorbed on the fcc-hollow, atop, and hcp-hollow sites in that order over Rh(111). The hcp-NO was inhibited by preadsorbed atop-CO, and fcc-NO and atop-NO were inhibited by CO preadsorbed on each type of the sites, indicating that NO and CO competitively adsorbed on Rh(111). From the Rh(111) surface-coadsorbed NO and CO, N 2 was produced by fcc-NO dissociation, and CO 2 was formed by reaction of adsorbed CO with O a from dissociated fcc-NO.

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Chemisorption geometry of NO on Rh(111) by X-ray photoelectron diffraction

Cited by 71 publications

References 40 publications

NO structures adsorbed on Rh(111): Theoretical approach to high-coverage STM images

NO structures adsorbed on Rh(111): Theoretical approach to high-coverage STM images

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

Adsorption Behavior and Reaction Properties of NO and CO on Ir(111) and Rh(111)

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