Evaporation of small fragments during the scattering of argon clusters at thermal kinetic energies from a graphite surface

Vach, Holger; Martino, A. De; Benslimane, M.; Châtelet, Madeleine; Pradère, F.

doi:10.1063/1.466752

Cited by 65 publications

(64 citation statements)

References 24 publications

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“…They measured the neutral flux from the surface and observed a peak at large scattering angles if the incident angle was not too steep. The appearance of a peak close to the tangential direction has been shown for other systems to be due to the survival of large cluster fragments [12][13][14]. In related work, surface scattering of clusters with impact velocities of 1-10 km/s has been shown to result in microshock wave propagation in the cluster which may induce intracluster reactions [15][16][17].…”

Section: Introductionmentioning

confidence: 86%

Ionization of water clusters by collisions with graphite surfaces

Andersson

Pettersson

1997

Z Phys D - Atoms, Molecules and Clusters

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We present experimental results on the scattering of neutral water clusters from graphite surfaces. We use cluster beams with an average cluster size up to 3700 molecules and an incident velocity of 1300 m/s, and study the emission of negatively and positively charged cluster fragments from the surface. The ionization probability is found to depend on cluster size and surface temperature, and for a given mean cluster size the emission rate of positive and negative cluster ions follows the Arrhenius equation. In the surface temperature range 950-1450 K, activation energies of 0.52±0.02 and 3.1 ± 0.3 eV are determined for the emission of positive and negative ions, respectively. The emission of negative cluster fragments is attributed to electron transfer from the surface, and we estimate an electron affinity of 1.4 ± 0.3 eV for large water clusters. Positive cluster fragments are proposed to be formed by dissocative ionization inside the cluster, followed by removal of the negative ion during surface contact.

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Section: Introductionmentioning

confidence: 86%

Ionization of water clusters by collisions with graphite surfaces

Andersson

Pettersson

1997

Z Phys D - Atoms, Molecules and Clusters

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“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] However, angle-resolved (AR) measurements [6][7][8][9][10][11][12] of internal energies have long been lacking in thermal surface reactions because of the difficulty in conducting such experiments, 18 although such measurements are required in order to obtain detailed structural information. In this paper, results of measurements of internal energies of AR product CO 2 in CO oxidation on Pd (110) are presented.…”

Section: Introductionmentioning

confidence: 99%

Angular dependence of rotational and vibrational energies of product CO2 in CO oxidation on Pd(110)

Yamanaka

2008

Phys. Chem. Chem. Phys.

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“…Elucidation of energy transfer dynamics, transition states (TSs), and their correlation to microscopic structures of substrates is essential to understand surface reactions at the atomic level [1][2][3][4][5][6][7][8][9][10][11][12], which is required to develop superior catalysts, electrodes, fuel cells, and material growth processes. Angle-resolved (AR) studies on product desorption in surface reactions and on surface scattering processes have provided indispensable information on the dynamics [6 -12].…”

mentioning

confidence: 99%

Polar- and Azimuth-Angle-Dependent Rotational and Vibrational Excitation of Desorbing ProductCO2in CO Oxidation on Palladium Surfaces

Yamanaka

Matsushima

2008

Phys. Rev. Lett.

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Clear polar and azimuth angle dependencies were found in rotational and vibrational energies of product CO 2 in CO oxidation on Pd surfaces. On Pd110-1 1, with increases in polar angle, both energies decreased in the [001] direction but remained constant in 1 10. On the Pd(110) with missing rows, both energies increased in [001] but decreased in 1 10, indicating that the transition state changes with the geometry of the substrate. On Pd(111), the rotational energy greatly increased, but the vibrational energy decreased. Such angular dependence of internal energy provides new dimensions in surface reaction dynamics. DOI: 10.1103/PhysRevLett.100.026104 PACS numbers: 82.65.+r, 68.35.Ja, 82.20.ÿw Elucidation of energy transfer dynamics, transition states (TSs), and their correlation to microscopic structures of substrates is essential to understand surface reactions at the atomic level [1][2][3][4][5][6][7][8][9][10][11][12], which is required to develop superior catalysts, electrodes, fuel cells, and material growth processes. Angle-resolved (AR) studies on product desorption in surface reactions and on surface scattering processes have provided indispensable information on the dynamics [6 -12]. However, compared with information on dynamics in gas-phase reactions, information on dynamics in surface reactions has been limited due to the fast energy relaxation of nascent products [13] and also due to the lack of AR measurements of the internal energy of products, which are necessary to obtain structural information on multidimensional dynamics and TS. In the gas-phase reaction, detailed shapes of the potential energy surface have been evaluated from internal energy since measurements are conducted in AR forms (although angles are usually defined relative to directions of molecular beams) [14]. On the other hand, in the surface reaction, there have been only a few works in which AR measurements of internal (only rotational) energy in photo-and electron-induced desorption were carried out [15][16][17], and no significant angular dependence was found. For surface thermal reactions, AR measurements of rotational and vibrational energies are still lacking. In this Letter, we describe clear polar and azimuth angle dependencies of vibrational and rotational energies of desorbing product CO 2 characteristic to surface structures in thermal CO oxidation on Pd(110) and Pd (111) surfaces, and we show a new approach to TS structures.CO oxidation on noble metals has long attracted the attention of chemists, physicists, and also mathematicians due to its practical importance and rich behaviors [1,6,[18][19][20][21][22][23][24][25][26]. It proceeds through adsorption of CO and dissociative adsorption of O 2 , diffusion of CO towards an O adatom, formation of a TS (O-CO-metal complex), and then repulsive desorption of CO 2 . Recently, structures and energies during formation processes of the TS have been studied in detail by ab initio calculations [23][24][25]. During desorption, the excess energy is partitioned into translatio...

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Evaporation of small fragments during the scattering of argon clusters at thermal kinetic energies from a graphite surface

Abstract: Photodissociation of hydrogen iodide on the surface of large argon clusters: The orientation of the librational wave function and the scattering from the cluster cage

Cited by 65 publications

References 24 publications

Ionization of water clusters by collisions with graphite surfaces

Ionization of water clusters by collisions with graphite surfaces

Angular dependence of rotational and vibrational energies of product CO2 in CO oxidation on Pd(110)

Polar- and Azimuth-Angle-Dependent Rotational and Vibrational Excitation of Desorbing ProductCO2in CO Oxidation on Palladium Surfaces

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