Effect of translational energy on the chemisorption of N2 on Fe(111): Activated dissociation via a precursor state

The initial dissociative chemisorption probability of N2 on Fe(111) is found to increase by a factor of 105 with increasing kinetic energy, rising from 1×10-6 at 0.09 eV to over 1×10-1 at 4.3 eV. This probability also increases with decreasing surface temperature, suggesting that reagent energy provides access to an intermediate state, such as ±-N2, whose population also increases with kinetic energy, consistent with the accepted mechanism at low energies. © 1987 The American Physical Society.