CO Oxidation over AuPd(100) from Ultrahigh Vacuum to Near-Atmospheric Pressures: The Critical Role of Contiguous Pd Atoms

CO Oxidation over AuPd(100) from Ultrahigh Vacuum to Near-Atmospheric Pressures: The Critical Role of Contiguous Pd Atom

Structure of Molecular-Sized Ru₃Sn₃ Clusters on a SiO₂ Film on Mo(112)

Triangular Ru3Sn3 clusters have been deposited on an ultra thin film of SiO2 on a Mo(112) surface from the cluster complex Ru3(CO)9(μ-SnPh2)3, were fixed by heating to 450 K under vacuum, and were then imaged by high resolution scanning tunneling microscopy. The clusters are preferentially oriented along the SiO4 chains and lie on top of a SiO4 group with attachments to neighboring SiO4 chains. At 700 K, the clusters migrate across the surface to step edges where fragmentation and agglomeration processes occur

Atomic-Scale Assembly of a Heterogeneous Catalytic Site

The distance between surface Pd atoms has been shown to control the catalytic formation of vinyl acetate from ethylene and acetic acid by AuPd catalysts. Here, we use the bulk alloy's thermodynamic properties, as well as the surface lattice spacing of a AuPd(100) alloy single-crystal model catalyst to control and optimize the concentration of the active site (Pd atom pairs at a specific Pd−Pd distance with Au nearest-neighbors). Scanning tunneling microscopy reveals that sample annealing has a direct effect on the surface Pd arrangements:  short-range order preferentially forms Pd pairs located in the c(2 × 2) sites, which are known to be optimal for vinyl acetate synthesis. This effect could be harnessed for future industrial catalyst design

Titania-Supported PdAu Bimetallic Catalysts Prepared from Dendrimer-Encapsulated Nanoparticle Precursors

We report the synthesis, characterization, and catalytic activity of titania-supported bimetallic PdAu particles prepared using dendrimer-encapsulated nanoparticle (DEN) precursors. Single-particle energy-dispersive spectroscopy indicates a homogeneous distribution of bimetallic nanoparticles having compositions closely related to the metal-ion ratios used to prepare the DEN precursors. The catalytic activity of the supported PdAu catalysts was compared to that of supported Pd-only and Au-only catalysts; the enhanced CO oxidation activity of the PdAu catalysts is indicative of a synergetic bimetallic interaction

Synthesis of CuPt Nanorod Catalysts with Tunable Lengths

Synthesis of CuPt Nanorod Catalysts with Tunable Length