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.