Adsorbed state and vibrational excitation of N 2 on Pd(110)

Abstract

High-resolution vibrational electron energy loss spectroscopy, low-energy electron diffraction and Auger electron spectroscopy have been used to study the interactions of nitrogen with the Pd(110) surface. At 120 K, N 2 is chemisorbed molecularly on the Pd(110) surface, and the (2 × 1)-N 2 structure is formed. Most probably, the N 2 molecules are chemisorbed in the on-top sites of the bulk-like Pd(110) surface in the upright-linear structure. The PdN 2 bond energy is estimated to be ~ 6 kcal/mol. The PdN 2 and NN stretching vibrations of N 2 admolecules on Pd(110) are observed at 30 and 278 meV, respectively. The primary-energy dependence and angle dependence of their excitation cross sections agree reasonably well with the prediction of the dipole theory. The electron beam-induced effects are briefly discussed.