NO Adsorption on 4d and 5d Transition-Metal (Rh, Pd, Ag, Ir, and Pt) Nanoparticles: Density Functional Theory Study and Supervised Learning

We studied the adsorption energies of the NO species on face-centered-cubic M-405-nanoparticles (NPs) (M = Rh, Pd, Ag, Ir, or Pt) using density functional theory calculations. Various adsorption sites including the on-top, bridge, and hollow sites in the ridge, (100) facet, and (111) facet were considered. The molecular adsorption energy on the slab model is affected by the adsorption configurations. By contrast, we observed different NO adsorption energies even for the same configuration on the same NP's surface facet, that is, the adsorptions of NO on the bridge sites in the (111) facets were different depending on the relative location from the ridge. The band center estimated from the partial density of states was correlated with the NO adsorption energy for the on-top site. However, when all adsorption sites were considered, the band center did not correlate well with the NO adsorption energy. We performed supervised learning for the calculated NO adsorption energies on M-405-NPs. Descriptors related to the second nearest-neighboring atoms to N and nearest-neighboring atoms to the adsorption site predicted the NO adsorption energy of all sites on M-405-NPs together with the d-band center of atoms in the adsorption site and its standard deviation.