Rhodium oxide films

Gottesfeld S (1980) The anodic rhodium oxide film a two-color electrochromic system. J Electrochem Soc 127 272-277... 

In Rutherford back scattering, RBS, one uses a primary beam of high energy H+ or He+ ions (1-5 MeV), which scatter from the nuclei of the atoms in the target. A fraction of the incident ions is scattered back and is subsequently analyzed for energy. As in LEIS, the energy spectrum represents a mass spectrum, but this time it is characteristic for the interior of the sample [7]. The technique has successfully been applied to determine the concentration of, for example, rhodium in model systems where the rhodium is present in sub monolayer quantities on thin, conducting oxide films [19]. 

An ideal study of support effects requires model catalysts with metal particles that are identical in size and shape (so that only the support oxide varies). This is difficult to achieve for impregnated catalysts, but identical metal particles can be prepared via epitaxial model catalysts [36]. Well-faceted Rh nanocrystals were grown on a 100-cm area NaCl(OOl) thin film at 598 K. One half of a Rh/NaCl sample was covered with Al Oj, and the other half with TiO. The preparation of Rh particles for both Al Oj- and TiO -supported model catalysts in a single step prevents any differences in particle size, shape, and surface structure which could occur if the samples were prepared in separate experiments. Three model catalysts were prepared, with a mean Rh particle size of 7.8, 13.3, and 16.7 mn (the films were finally removed from the NaCl substrate by flotation in water). Activation was performed by O /H treatments, with the structural changes followed by TEM (Fig. 15.6). Oxidation was carried out in 1 bar O at 723 K prodncing an epitaxially grown rhodium oxide shell on a Rh core (cf Fig. 15.5e), whereas the hydrogen reduction temperature was varied. 

In a further examination of the hydrous rhodium oxide system Burke and O Sullivan42 showed that thick films grown by fast cycling procedures were only partially active with regard to charge storage... 

Temperature Dependence of Growth of Snrface Oxide Films on Rhodium Electrodes... 

VILUARD JERKIEWICZ Siaface Oxide Films Rhodium Electrodes 325... 

VILLIARD JERKIEWICZ Surface Oxide Films Rhodium Electrodes 331... 

VILUARD JERKIEWICZ Swface Oxide Films Rhodium Electrodes 333... 

VILLIARD JERKIEWICZ Sutface Oxide Films Rhodium Electrodes 341... 

Under severe conditions and at high temperatures, noble metal films may fail by oxidation of the substrate base metal through pores in the film. Improved life may be achieved by first imposing a harder noble metal film, eg, rhodium or platinum—iridium, on the substrate metal. For maximum adhesion, the metal of the intermediate film should ahoy both with the substrate metal and the soft noble-metal lubricating film. This sometimes requires more than one intermediate layer. For example, silver does not ahoy to steel and tends to lack adhesion. A flash of hard nickel bonds weh to the steel but the nickel tends to oxidize and should be coated with rhodium before applying shver of 1—5 p.m thickness. This triplex film then provides better adhesion and gready increased corrosion protection. 

Miscellaneous. Ruthenium dioxide-based thick-film resistors have been used as secondary thermometers below I K (92). Ruthenium dioxide-coated anodes ate the most widely used anode for chlorine production (93). Ruthenium(IV) oxide and other compounds ate used in the electronics industry as resistor material in apphcations where thick-film technology is used to print electrical circuits (94) (see Electronic materials). Ruthenium electroplate has similar properties to those of rhodium, but is much less expensive. Electrolytes used for mthenium electroplating (95) include [Ru2Clg(OH2)2N] Na2[Ru(N02)4(N0)0H] [13859-66-0] and (NH 2P uds(NO)] [13820-58-1], Several photocatalytic cycles that generate... 

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