Rotationally inelastic scattering of N2 from clean and hydrogen covered Pd(111)

Quantum-resolved molecular beam–surface scattering from clean and hydrogen covered Pd(111) is shown to be a sensitive dynamical probe of changes in the gas–surface interaction potential brought about by the presence of chemisorbed surface hydrogen. In particular, the specular scattering of N2 from hydrogen covered Pd(111) is appreciably less inelastic rotationally than scattering from the clean surface. The specularly scattered rotationally elastic channel is utilized as a nonperturbative probe of the surface chemisorbed hydrogen coverage during a temperature programmed desorption (TPD) experiment.