Vibrational Energy Redistribution in a Gas-Surface Encounter: State-to-State Scattering of CH4 from Ni(111)

Abstract

The fate of vibrational energy in the collision of methane (CH_{4}) in its antisymmetric C-H stretch vibration (ν_{3}) with a Ni(111) surface has been studied in a state-to-state scattering experiment. Laser excitation in the incident molecular beam prepared the J=1 rotational state of ν_{3}, and a bolometer in combination with selective laser excitation detected the scattered methane. The rovibrationally resolved scattering distributions reveal very efficient vibrational energy redistribution from ν_{3} to the symmetric C-H stretch vibration (ν_{1}). The branching ratio ν_{1}/ν_{3} is near 0.4 and insensitive to changes in incident kinetic energy in the range from 100 to 370 meV. State-resolved angular distributions and measurements of the residual Doppler linewidths prove that the scattering is direct. The observed vibrationally inelastic scattering provides direct experimental evidence for surface-induced vibrational energy redistribution.

Computational approaches to dissociative chemisorption on metals: towards chemical accuracy

“…Very recently, the SRP32-vdW1 DF has been used in RPH calculations on vibrationally inelastic scattering of (n 3 = 1) CH 4 from Ni (111) and Ni (111) covered by a monolayer of graphene (Gr/Ni (111)). 673 In agreement with recent experiments, 240 the calculations revealed substantial vibrationally inelastic scattering to the (n 1 = 1) symmetric stretching state (also called surface induced IVR). 673 Again in agreement with experiment, 240 hardly any vibrationally inelastic scattering to excited bending states was observed, and hardly any vibrationally inelastic scattering was found in scattering from Gr/Ni (111).…”

“…673 In agreement with recent experiments, 240 the calculations revealed substantial vibrationally inelastic scattering to the (n 1 = 1) symmetric stretching state (also called surface induced IVR). 673 Again in agreement with experiment, 240 hardly any vibrationally inelastic scattering to excited bending states was observed, and hardly any vibrationally inelastic scattering was found in scattering from Gr/Ni (111). 673 The calculations showed a strong dependence of the vibrationally inelastic scattering probability on impact site, with a high excitation probability correlating with a high catalytic activity of the site.…”

“…The DC of methane and its isotopologues has become a paradigm for non-statistical reactive scattering. 14,[18][19][20]201 New experiments challenging theory continue to evolve on DC 21,44,47,162,165,181,182,[235][236][237][238][239] as well as vibrationally inelastic 240 and diffractive 27 scattering, and physisorption. 241 Recently initial-state selected DC of water (D 2 O) was studied for the first time in a supersonic MB experiment.…”

Alignment-resolved O2 scattering from highly oriented pyrolytic graphite and LiF(001) surfaces

“…State-resolved molecular beam-surface scattering experiments, which specify the geometry and internal states of incident and/or scattered molecules, provide valuable information not only on the geometrical effect in the molecule-surface interaction, but also on the mechanism of energy dissipation of impinging molecules necessary to result in trapping or chemisorption [1][2][3][4][5][6]. The geometrical effect here is usually classified into two categories.…”

Setting benchmarks for modelling gas–surface interactions using coherent control of rotational orientation states

“…Significant efforts are being made to develop reliable multi-dimensional potential energy surfaces, which can be used to study molecule-surface collisions and heterogeneous catalysis [54][55][56] . Up to now, the probabilities that molecules scatter into elastic and inelastic diffraction channels provided a sensitive way of benchmarking theoretical interaction models [35][36][37][38][57][58][59] , in addition to state-resolved sticking measurements which provide valuable complementary information for the reaction probabilties [60][61][62] . Comparing calculated S-matrices, once these become available, with experimentally determined values of the type reported in this paper, will provide an extremely sensitive, and particularly valuable benchmark for assessing theoretical models.…”