Publications de Helen Jane Chadwick

CHD3 Dissociation on the Kinked Pt(210) Surface: A Comparison of Experiment and Theory

Rainer Beck, Helen Jane Chadwick, Ana Gutiérrez González

To be able to simulate activated heterogeneously catalyzed reactions on the edge and corner sites of nanoparticles, a method for calculating accurate activation barriers for the reactions is required. We have recently demonstrated that a semiempirical spec ...

2019

Transferability of the SRP32-vdW specific reaction parameter functional to CHD3 dissociation on Pt(110)-(2 × 1)

Rainer Beck, Helen Jane Chadwick, Ana Gutiérrez González

Stepped transition metal surfaces, including the reconstructed Pt(110)-(2 × 1) surface, can be used to model the effect of line defects on cata- lysts. We present a combined experimental and theoretical study of CHD3 dissociation on this surface. Theoretic ...

2019

Methane dissociation on the steps and terraces of Pt(211) resolved by quantum state and impact site

Rainer Beck, Helen Jane Chadwick, Ana Gutiérrez González

Methane dissociation on the step and terrace sites of a Pt(211) single crystal was studied by reflection absorption infrared spectroscopy (RAIRS) at a surface temperature of 120 K. The C−H stretch RAIRS signal of the chemisorbed methyl product species was ...

American Institute of Physics2018

Quantum State–Resolved Studies of Chemisorption Reactions

Rainer Beck, Helen Jane Chadwick

Chemical reactions at the gas–surface interface are ubiquitous in the chemical industry as well as in nature. Investigating these processes at a microscopic, quantum state–resolved level helps develop a predictive understanding of this important class of r ...

Annual Reviews2017

Quantum state resolved gas–surface reaction dynamics experiments: a tutorial review

Rainer Beck, Helen Jane Chadwick

We present a tutorial review of our quantum state resolved experiments designed to study gas–surface reaction dynamics. The combination of a molecular beam, state specific reactant preparation by infrared laser pumping, and ultrahigh vacuum surface analysi ...

Royal Society of Chemistry2016

Quantum state resolved molecular beam reflectivity measurements: CH4 dissociation on Pt(111)

Rainer Beck, Helen Jane Chadwick, Ana Gutiérrez González

The King and Wells molecular beam reflectivity method has been used for a quantum state resolved study of the dissociative chemisorption of CH4 on Pt(111) at several surface temperatures. Initial sticking coefficients were measured for incident CH4 prepare ...

American Institute of Physics2016

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

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

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

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

Rainer Beck, Hirokazu Ueta, Maarten Eduard van Reijzen, Helen Jane Chadwick, 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 specific reactant preparation in a molecular beam by rapid adiabatic passage

Rainer Beck, Bruce Yoder, Phil Morten Hundt, Maarten Eduard van Reijzen, Helen Jane Chadwick

Highly efficient preparation of molecules in a specific rovibrationally excited state for gas/surface reactivity measurements is achieved in a molecular beam using tunable infrared (IR) radiation from a single mode continuous wave optical parametric oscill ...

American Institute of Physics2014