Ruthenium Cluster Structure Change Induced by Hydrogen Adsorption: Ru₁₉^–

Abstract

The effect of hydrogenation on the structure of Ru19 – has been studied using a combination of trapped ion electron diffraction and density functional computations. While the bare Ru19 – cluster has a closed-shell octahedral geometry, hydrogenation of the cluster changes the structure type of the ruthenium core toward an icosahedral motif. The experiments show a gradual structural transition depending on the number of adsorbed hydrogen atoms. Density functional theory computations reveal the driving force behind this process to be the larger hydrogen adsorption energies for the bi-icosahedral structure and predict a corresponding structural rearrangement at around 20 adsorbed hydrogen atoms, which is consistent with the experimental findings. Additionally, the computations provide insight into the hydrogen-binding situation. They show that hydrogen is preferentially atomically bound only to surface Ru atoms. H2 binding is predicted only at high hydrogen loadings.

Hydrogen Chemisorption on Doubly Vanadium Doped Aluminum Clusters

“…n = 4 and 8, there is a considerable change in geometry going from the molecularly adsorbed lowest-energy isomer to the dissociatively adsorbed structure. Although such structural changes are often accompanied by an energy barrier [28], theoretical calculations indicate that for aluminum clusters these barriers can be offset by the adsorption energy of dissociatively adsorbed hydrogen [29]. From Figure 3 it can be seen that there is some correlation between the molecular binding energy, the H-H bond distance and the experimental abundances.…”

σ-H–H, σ-C–H, and σ-Si–H Bond Activation Catalyzed by Metal Nanoparticles

“…50 Bumüller and co-workers have recently reported on DFT calculations of H2 adsorption onto Ru nanoclusters of 19 Ru atoms. 64 In contrast to large Ru NPs, which present an hcp structure, Ru19possesses a closed-shell octahedral fcc structure. Interestingly, in the Ru19Dxnanocluster range containing 0 to 40 D atoms, there is a transition from the octahedral fcc to a bi-icosahedral structure at 20 D atoms, to maximize the adsorption energy of D. In addition, hydrogen atoms coordinate at two-fold sites on both cluster core motifs, in contrast to flat surfaces where a three-fold coordination is preferred.…”

Mechanochemically Assisted Synthesis of Ruthenium Clusters Embedded in Mesoporous Carbon for an Efficient Hydrogen Evolution Reaction

“…One of the theoretically and experimentally effective solution is to downsize the Ru species with high dispersion. This is because smaller Ru nanostructures ensure the exposure of more catalytically active edge or corner sites, which can significantly boost the HER performance, and eventually enhance the atomic economy of Ru electrocatalysts . To this end, well‐defined Ru catalysts with uniformly dispersed small Ru nanoparticles,, Ru clusters and Ru single atoms have been proposed recently.…”