Speaker
Description
Understanding the interaction between reactant molecules and “single-atom” active sites is important for comprehending the evolution of single-atom catalysts in reactive atmospheres. Here, we study the interaction between CO and Rh$_{1}$ and Rh$_{2}$ species supported by Fe$_{3}$O$_{4}$(001) using DFT and experimental surface science techniques. Stable Rh$_{1}$(CO)$_{1}$ is formed via CO adsorption at both 2-fold and 5-fold to oxygen-coordinated Rh$_{1}$ sites. While DFT suggests Rh$_{1}$(CO)$_{2}$ to be energetically favorable, only a minority of these are observed experimentally. Instead, the limited Rh$_{1}$(CO)$_{2}$ is observed experimentally via CO-induced Rh$_{2}$ dimer breakup. Experiment and DFT results suggest this process occurs via an unstable Rh$_{2}$(CO)$_{3}$ intermediate.