Silver-palladium

Electronic Applications. The PGMs have a number of important and diverse appHcations in the electronics industry (30). The most widely used are palladium and mthenium. Palladium or palladium—silver thick-film pastes are used in multilayer ceramic capacitors and conductor inks for hybrid integrated circuits (qv). In multilayer ceramic capacitors, the termination electrodes are silver or a silver-rich Pd—Ag alloy. The internal electrodes use a palladium-rich Pd—Ag alloy. Palladium salts are increasingly used to plate edge connectors and lead frames of semiconductors (qv), as a cost-effective alternative to gold. In 1994, 45% of total mthenium demand was for use in mthenium oxide resistor pastes (see Electrical connectors). 

Isotope Effects on Superconductivity. Substitution of hydrogen by deuterium affects the superconducting transition temperature of palladium hydride [26929-60-2] PdH2 (54,55), palladium silver hydride, Pd Ag H D ( 6), and vanadium—2itconium—hydride, N(57). 

Palladium-silver alloy has greater resistance to fretting. Inlays are common, and coatings will be adopted as deposition processes improve. ... 

Catalysts. The methanation of CO and C02 is catalyzed by metals of Group VIII, by molybdenum (Group VI), and by silver (Group I). These catalysts were identified by Fischer, Tropsch, and Dilthey (18) who studied the methanation properties of various metals at temperatures up to 800°C. They found that methanation activity varied with the metal as follows ruthenium > iridium > rhodium > nickel > cobalt > osmium > platinum > iron > molybdenum > palladium > silver. 

The disappearance of the paramagnetism of palladium-silver alloys (rich in Pd) when the ratio (H + Ag)/Pd = 0.6 (24) illustrates that the effect of both these alloying" elements in palladium is additive and each one contributes essentially in the same way to the change of magnetic susceptibility of palladium. 

Silver-palladium alloys, see Palladium-silver alloys... 

Rubidium Strontium Yttrium Zircomum Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium indium Tin Antimony IJtunum Iodine Xenon... 

Selective gas permeation has been known for generations, and the early use of palladium silver-alloy membranes achieved sporadic industrial use. Gas separation on a massive scale was used to separate U from U using porous (Knudsen flow) membranes. An upgrade of the membranes at Oak Ridge cost 1.5 billion. Polymeric membranes became economically viable about 1980, introducing the modern era of gas-separation membranes. H2 recovery was the first major application, followed quickly by acid gas separation (CO2/CH4) and the production of N2 from air. 

Soma-Noto Y, Sachtler WMH. 1974. Infrared spectra of carbon monoxide adsorbed on supported palladium and palladium-silver alloys, J Catal 32 315. 

Anderson and Kemball (35) examined the reaction between gaseous deuterium and benzene catalyzed by evaporated films of iron, nickel, palladium, silver, tungsten, and platinum. The order of reactivity (estimated from the temperature at which the addition reaction achieved an initial rate of 1% per minute for a 10 mg film at certain specified reactant... 

Most of the work initially was with the more volatile transition metals, i.e. the first row metals plus palladium, silver and gold, because these were easy to evaporate in reasonable quantities in simple apparatus. However, efforts to use the less volatile metals of the second and third rows gained momentum. Skell used sublimation of resistively heated wires of molybdenum and tungsten to make the remarkably stable [Mo(rj4-C4H6)3] and [W(1j4-C4H6)3] (42). Green... 

Uemiya, S., T. Matsuda, and E. Kikuchi, Hydrogen permeable palladium-silver alloy membrane supported on porous ceramics, /. Membr. Sci., 56, 315,1991b. 

Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon... 

Palladium-silver alloy membranes, 15 813-814 Pall rings, 1 28 8 770... 

Siloxane compounds, in vitreous silica manufacture, 22 414 Siloxane materials, 20 240 Siloxane oligomers, in silicone polymerization, 22 555-556 Siloxanols, silylation and, 22 703 Silsesquioxane hybrids, 13 549 Silsesquioxanes, 15 188, 22 589-590 SilvaGas process, 3 696, 697 Silver (Ag), 22 636-667. See also Silver compounds. See Ag entries Argentothiosulfate complexes Batch desilverizing Lead-silver alloys Palladium-silver alloy membranes analytical methods for, 22 650-651 applications of, 22 636-637, 657-662 as bactericide, 22 656, 657, 660 barium alloys with, 3 344 in bimetallic monetary system, 22 647-648 in cast dental gold alloys, 8 307t coke formation on, 5 266 colloidal precipitation color, 7 343t colloidal suspensions, 7 275 color, 7 334, 335... 

Hydrogenation of Acetylene on Bimetallic Palladium-Silver Catalysts... 

Nonporous palladium/silver tube (23 wt.Vo silver, in double pipe configuration), wall thickness 0.2 mm, outer diameter 10.8 mm, length 24.3 cm. Feed enters the reactor at tube side, permeate at shell side. 

Guryanova, S. G., V. M. Gryaznov and S. Kanizius. 1973. Selective hydrogenation of acetylene on a palladium-silver membrane catalyst. Analiz Soverm. Zadach u Tech. Naukakh 172. 

The reversible absorption was observed to proceed in presence of either metallic palladium or in palladium-silver alloys much less hydrogen was absorbed in Cu sponge (1 vol. Cu 0.6 vol. H.), and not at all in Os-Ir. The reaction of hydrogen with palladium, so being described by Graham, was ... 

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