Dissociation of physisorbed H2 through low-energy electron scattering resonances

Quantum and classical dynamics of reactive scattering of H2 from metal surfaces

State-of-the-art theoretical models allow nowadays an accurate description of H₂/metal surface systems and phenomena relative to heterogeneous catalysis. Here we review the most relevant ones investigated during the last 10 years.

Desorption of H2, HD, and D2 through temporary negative ion formation

Physically adsorbed H(2), HD, and D(2) desorbs via the low-energy 2Σ(u)+ electron scattering resonance with characteristic electron energy dependent cross sections as we show by desorption and electron energy-loss measurements. Only H(2) and HD desorb, for energetic reasons, via excitation of the j = 0 → 2 rotational mode and its subsequent decay into free translational motion, while all three isotopes desorb by direct transitions to unbound continuum states, with a probability close to unity and an unexpectedly weak mass dependence ~m(-1/2).