Conclusions
This study had two objectives. The first was to calculate local adsorption characteristics – binding sites, bond distances, adsorption energies, and vibrational spectra for select intermediates involved in the ammonia synthesis reaction on pure iridium. These intermediates are N2, N, NH, NH2, and NH3. Secondly, three DFT methods – B3LYP, B3LYP-D3, and B97-D3 – were compared to determine the effect dispersion has on the popular B3LYP method and contrast it with a faster semi-empirical GGA, B97-D3.