ROLE OF VIBRATIONAL AND TRANSLATIONAL ENERGY IN THE ACTIVATED DISSOCIATIVE ADSORPTION OF D2 ON CU(111)

We report the relative efficacy of vibrational and translational energy in overcoming the barrier to dissociative adsorption of D2 on a Cu(111) surface. This is determined by measuring variation of adsorption probability with kinetic energies, E(i), and vibrational temperature. At the highest energy (E(i) = 0.83 eV) adsorption is predominantly due to ground-state D2; molecules in excited vibrational states play the dominant role for E(i) below approximately 0.5 eV. A detailed analysis provides estimated adsorption probability versus energy functions for D2 in vibrational states-nu = 0 to nu = 3.