NO Binding Energies to and Diffusion Barrier on Pd Obtained with Velocity-Resolved Kinetics

Abstract

We report nitric oxide (NO) desorption rates from Pd(111) and Pd(332) surfaces measured with velocity-resolved kinetics. The desorption rates at the surface temperatures from 620 to 800 K span more than 3 orders of magnitude, and competing processes, like dissociation, are absent. Applying transition state theory (TST) to model experimental data leads to the NO binding energy <i>E</i> ₀ = 1.766 ± 0.024 eV and diffusion barrier <i>D</i> _T = 0.29 ± 0.11 eV on the (111) terrace and the stabilization energy for (110)-steps Δ<i>E</i> _ST = 0.060_-0.030 ^+0.015 eV. These parameters provide valuable benchmarks for theory.