Rh Single-Atom Catalyst Configurations on Ni, Cu, Pd, Ag, Ir, Pt, and Au Nanoparticles

The stability of single-atom dopants across nanoparticle shapes and surface sites guides the design of heterogeneous catalysts for thermal and electrochemical processes. In this work, we use spin-polarized density functional theory (DFT) calculations on four Wulff-constructed face-centered cubic (FCC) nanoparticle shapes across seven hosts (Ni, Cu, Pd, Ag, Ir, Pt, and Au) to compute site-resolved Rh formation energies. Only Ir shows consistently negative formation energies for Rh-substitution, with the lowest value of −0.75 eV at corner sites. The lowest formation energies of Rh-substitution on Ni and Cu are close to zero (−0.015 and −0.007 eV, respectively), whereas all tested surface configurations on Pd, Ag, Pt, and Au have positive formation energies and are thermodynamically unfavorable. Local strain correlates with formation energy across hosts, but not across shapes and sites within a host. Among the descriptors we considered, the Rh d-band center, ϵ d, has the strongest global linear correlation with formation energy (Pearson R = 0.86), though the correlation reverses within Ir, where coordination effects become important. A Sure Independence Screening and Sparsifying Operator (SISSO) model using only the host FCC bulk descriptors and coordination at the corresponding pristine site captures the stability ordering, enabling screening before explicit DFT calculations. These results identify Ir-based hosts and low-coordination sites as candidate starting points for shape-controlled Rh single-atom catalysts.