Non-adiabaticity in surface chemical reactions

Hasselbrink, Eckart

doi:10.1016/j.susc.2008.12.037

Cited by 38 publications

(31 citation statements)

References 70 publications

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“…However, the relevant energy exchange processes arising form the reactive gas/metal surface interactions and leading to the chemically induced excitation of energetic electrons on metal surfaces without resorting to heat ͑as during photoexcitation of electrons in photovoltaic devices͒ are insufficiently understood at the present time. 3,12,15 Besides, the quantum efficiency, number of electron generated per reaction event, of the systems studied by this time is relatively low being in the range of 10 −4 -10 −3 . Therefore, elucidation of basic properties this process for various metal-semiconductor heterostructures is very important for the development of nonadiabatic chemical-to-electrical energy conversion devices.…”

Section: Introductionmentioning

confidence: 92%

“…The energetic effects of surface recombination of hydrogen derived radicals are 1.17 eV and 0.91 eV for the H + OH → H 2 O and OH+ OH→ O+H 2 O processes, respectively. [15][16][17] These two reactions comprise the last step in the catalytic oxidation of hydrogen to water on metal surfaces. 15,17 The energy released in these processes may dissipate nonadiabatically via the direct excitation of electrons with energies 1 eV above the Fermi level in the metal film.…”

Section: Basic Mechanismsmentioning

confidence: 99%

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Nonadiabatic chemical-to-electrical energy conversion in heterojunction nanostructures

Karpov

Nedrygailov

2010

Phys. Rev. B

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Nonadiabatic energy dissipation by electron subsystem of nanostructured solids unveil interesting opportunities for the solid-state energy conversion and sensor applications. We found that planar Pt/GaP and Pd/GaP Schottky structures with nanometer thickness metallization demonstrates a nonadiabatic channel for the conversion into electricity the energy of a catalytic hydrogen-to-water oxidation process on the metal layer surface. The observed above thermal current greatly complements the usual thermionic emission current and its magnitude is linearly proportional to the rate of formation and desorption of product water molecules from the nanostructure surface. The possibilities of utilizing the nonadiabatic functionality in chemical-to-electrical energy conversion devices are discussed.

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Section: Introductionmentioning

confidence: 92%

Section: Basic Mechanismsmentioning

confidence: 99%

Nonadiabatic chemical-to-electrical energy conversion in heterojunction nanostructures

Karpov

Nedrygailov

2010

Phys. Rev. B

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“…Experiments developed during the last few years have measured, for example, chemicurrents and creation of hot electrons during the chemisorption of atoms and molecules on metal films and surfaces, [1][2][3][4][5] highly efficient multi-quantum vibrational relaxation of highly vibrationally excited NO molecules scattered from metal surfaces, 6,7 and even electron emission upon scattering of highly vibrationally excited NO from a low work function metal surface. 8 Nevertheless, the fundamental question to be answered now is: how much does the presence of electronic excitations influence the interactions between molecules and metal surfaces?…”

Section: Introductionmentioning

confidence: 99%

Vibrational deexcitation and rotational excitation of H2 and D2 scattered from Cu(111): Adiabatic versus non-adiabatic dynamics

Muzas

Juaristi

Alducin

et al. 2012

The Journal of Chemical Physics

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We have studied survival and rotational excitation probabilities of H 2 (v i = 1, J i = 1) and D 2 (v i = 1, J i = 2) upon scattering from Cu(111) using six-dimensional (6D) adiabatic (quantum and quasi-classical) and non-adiabatic (quasi-classical) dynamics. Non-adiabatic dynamics, based on a friction model, has been used to analyze the role of electron-hole pair excitations. Comparison between adiabatic and non-adiabatic calculations reveals a smaller influence of non-adiabatic effects on the energy dependence of the vibrational deexcitation mechanism than previously suggested by low-dimensional dynamics calculations. Specifically, we show that 6D adiabatic dynamics can account for the increase of vibrational deexcitation as a function of the incidence energy, as well as for the isotope effect observed experimentally in the energy dependence for H 2 (D 2 )/Cu(100). Furthermore, a detailed analysis, based on classical trajectories, reveals that in trajectories leading to vibrational deexcitation, the minimum classical turning point is close to the top site, reflecting the multidimensionally of this mechanism. On this site, the reaction path curvature favors vibrational inelastic scattering. Finally, we show that the probability for a molecule to get close to the top site is higher for H 2 than for D 2 , which explains the isotope effect found experimentally.

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“…1a). It is also assumed that adatoms enter the potential well from the upper bound state at energy Е* and dissipate their energy into the solid via the excita tion of phonons and electron hole-pairs [1]. The dissi pation of the energy of the adatom into the solid, from energy state E to Е -η, is described through the rate coefficient К(Е, Е -η); in turn the rate coefficient of the reverse process is attained from detailed balancing…”

Section: Master Equation For a Continuum Set Of Energy Levelsmentioning

confidence: 99%

“…In the last section the occurrence of hyper thermal df and their relevance to 'hot atom' reactions is examined and discussed. 1 The article is published in the original.…”

Section: Introductionmentioning

confidence: 99%

Hyperthermal energy distribution functions of the adspecies in recombinative adsorption at catalytic surfaces and their relevance to ‘hot atom’ reactions

Molinari

Tomellini

2013

Kinet Catal

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Abstract-We report on the modeling of the energy distribution functions of the adspecies in diatom forma tion at catalytic surfaces under steady state conditions. To this end master equations are employed, in the case of either continuous or discrete set of adatom energy levels in the adsorption potential well, and the impact of the distribution function on reaction rate investigated. The transition from thermal to hyperthermal reac tion rates has been studied as a function of rate coefficients for recombination and energy dissipation pro cesses. Experimental data available from the literature, have been analysed in the framework of the theoreti cal model. It is shown that hyperthermal energy distribution functions entail a "hot atom" reaction mecha nism.

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Non-adiabaticity in surface chemical reactions

Cited by 38 publications

References 70 publications

Nonadiabatic chemical-to-electrical energy conversion in heterojunction nanostructures

Nonadiabatic chemical-to-electrical energy conversion in heterojunction nanostructures

Vibrational deexcitation and rotational excitation of H2 and D2 scattered from Cu(111): Adiabatic versus non-adiabatic dynamics

Hyperthermal energy distribution functions of the adspecies in recombinative adsorption at catalytic surfaces and their relevance to ‘hot atom’ reactions

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