Publications de Hirokazu Ueta | EPFL Graph Search

The Negligible Role of C-H Stretch Excitation in the Physisorption of CH4 on Pt(111)

Rainer Beck, Li Chen, Helen Jane Chadwick, Hirokazu Ueta

We report a molecular beam study of the effect of vibrational excitation on the physisorption of methane on a Pt(111) surface. Our experiments use a continuous molecular beam of CH4, prepared in its antisymmetic C-H stretch mode ν3 by infrared laser pumpin ...

American Chemical Society2015

State-Resolved Methane Dissociation on Pt(111) Studied by Reflection Absorption Infrared Spectroscopy

Rainer Beck, Hirokazu Ueta, Li Chen

The dissociation of methane on Pt(111) was studied using quantum state-resolved methods and reflection absorption infrared spectroscopy (RAIRS), at a surface temperature of 150 K where the nascent reaction products methyl(ads) and H(ads) are stable and acc ...

2015

Bond-Selective and Mode-Specific Dissociation of CH3D and CH2D2 on Pt(111)

Rainer Beck, Hirokazu Ueta, Phil Morten Hundt, Maarten Eduard van Reijzen

Infrared laser excitation of partially deuterated methanes (CH3D and CH2D2) in a molecular beam is used to control their dissociative chemisorption on a Pt(111) single crystal and to determine the quantum state-resolved dissociation probabilities. The excl ...

American Chemical Society2015

Vibrational Activation of Methane Chemisorption: The Role of Symmetry

Rainer Beck, Hirokazu Ueta, Phil Morten Hundt, Maarten Eduard van Reijzen

Quantum state-resolved reactivity measurements probe the role of vibrational symmetry on the vibrational activation of the dissociative chemisorption of CH4 on Pt(111). IR–IR double resonance excitation in a molecular beam is used to prepare CH4 in all thr ...

Amer Chemical Soc2014

Ab Initio Molecular Dynamics Calculations versus Quantum-State- Resolved Experiments on CHD3 + Pt(111): New Insights into a Prototypical Gas−Surface Reaction

Rainer Beck, Helen Jane Chadwick, Hirokazu Ueta, Maarten Eduard van Reijzen, Francesco Nattino

The dissociative chemisorption of methane on metal surfaces is of fundamental and practical interest, being a rate-limiting step in the steam reforming process. The reaction is best modeled with quantum dynamics calculations, but these are currently not gu ...

Amer Chemical Soc2014

Quantum state-resolved CH4 dissociation on Pt(111): coverage dependent barrier heights from experiment and density functional theory

Rainer Beck, Hirokazu Ueta, Li Chen

The dissociative chemisorption of CH4 on Pt(111) was studied using quantum state-resolved methods at a surface temperature (Ts) of 150 K where the nascent reaction products CH3(ads) and H(ads) are stable and accumulate on the surface. Most previous experim ...

Royal Society of Chemistry2013

Quantum state-resolved gas/surface reaction dynamics probed by reflection absorption infrared spectroscopy

Rainer Beck, Régis Bisson, Li Chen, Hirokazu Ueta

We report the design and characterization of a new molecular-beam/surface-science apparatus for quantum state-resolved studies of gas/surface reaction dynamics combining optical state-specific reactant preparation in a molecular beam by rapid adiabatic pas ...

American Institute of Physics2013

Vibrationally bond-selected chemisorption of methane isotopologues on Pt(111) studied by reflection absorption infrared spectroscopy

Rainer Beck, Régis Bisson, Li Chen, Hirokazu Ueta

Reflection absorption infrared spectroscopy (RAIRS) was used to probe for vibrational bond-selectivity in the dissociative chemisorption of three partially deuterated methane isotopologues on a Pt(111) surface. While a combination of incident translational ...

Royal Society of Chemistry2012

Evidence of stable high-temperature D-x-CO intermediates on the Ru(0001) surface

Hirokazu Ueta

We demonstrate the formation of complexes involving attractive interactions between D and CO on Ru(0001) that are stable at significantly higher temperatures than have previously been reported for such intermediate species on this surface. These complexes ...

2012