Low power consumption and minimal potential hazards are ultimate goals for the modern development of chemical manufacturing; however, it often reduces the selectivity of chemical reactions by implementing a new reaction system. A nanocatalyst design is reported for achieving efficient and selective alkyne semihydrogenation through the photocatalytic hydrogen transfer from water, which avoids th...

Using low energy electron microscopy we observe that Pd deposited on Ru only attaches to small sections of the atomic step edges surrounding Pd islands. This causes a novel epitaxial growth mode in which islands advance in a snakelike motion, giving rise to labyrinthine patterns. Based on density functional theory together with scanning tunneling microscopy and low energy electron microscopy we...

Palladium is a frequently used model system for hydrogen storage. During the past few decades, particular interest was placed on the superior H-absorption properties of nanostructured Pd systems. In the present study nanoporous palladium (np-Pd) is produced by electrochemical dealloying, an electrochemical etching process that removes the less noble component from a master alloy. The volume and...

Owing to a lack of microstructure, glassy materials are inherently strong but brittle, and often demonstrate extreme sensitivity to flaws. Accordingly, their macroscopic failure is often not initiated by plastic yielding, and almost always terminated by brittle fracture. Unlike conventional brittle glasses, metallic glasses are generally capable of limited plastic yielding by shear-band sliding...

The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circui...

Palladium, rhodium and their alloys were studied in a diamond anvil cell in a high pressure hydrogen atmosphere up to 20 GPa by X-ray diffraction at room temperature. Formation of a monohydride with H/(Rh þ Pd) 1⁄4 1 ratio was observed for each alloy at hydrogen pressures less than 3 GPa. The corresponding volume expansion of the metal lattice was 2.2 e2.8 Å per metal atom. A formation of the d...

Using low-energy electron microscopy, we measure the diffusion of Pd into bulk Cu at the Cu(100) surface. Interdiffusion is tracked by measuring the dissolution of the Cu(100)-c(2 × 2)-Pd surface alloy during annealing (T>240 °C). The activation barrier for Pd diffusion from the surface alloy into the bulk is determined to be (1.8 ± 0.6) eV. During annealing, we observe the growth of a new laye...

Metal alloys consisting of a platinum group metal—ruthenium, rhodium, palladium, osmium, iridium or platinum—and one or more transition metals are important for catalytic reactions in automobiles, chemistry, and petroleum production. In addition, many of the alloys used in aeronautics and electronics contain platinum group metals. Alloys beyond those currently used in these industries could be ...

The effect of 5 different surface conditioning methods on bonding of metal brackets to cast dental alloys was examined. The surface conditioning methods were fine (30-microm) or rough (125-microm) diamond bur, sandblasting (50-microm or 110-microm aluminum oxide [Al2O3]), and silica coating (30-microm silica). Fifty disc-shaped specimens of 5 different alloys (gold-silver, palladium-silver, nic...