Browsing by Author "Katayama, Akiko"

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    Adsorption of hydrogen on a platinum–graphite catalyst. Part 1.—Electron spin resonance measurement in the gas–solid system
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1978, 74 (08), 1978) Katayama, Akiko; Kita, Hideaki
    E.s.r. signals from a platinum–graphite catalyst (Pt–graphite) and pure graphite were observed as functions of hydrogen gas pressure, temperature and the amount of platinum. The signals were inferred to be due to conduction charge carriers. The e.s.r. signal of Pt–graphite exhibits behaviour similar to that of pure graphite with respect to the temperature variation of the g∥ value. The signal from pure graphite was not affected by the presence of hydrogen gas. However, the signal from Pt–graphite at g=ge(g value of a free electron) decreased with the amount of platinum and increased with the increment in hydrogen gas pressure, obeying the non-dissociative Langmuir isotherm. Detailed analysis indicated that the adsorption of hydrogen on Pt–graphite causes a change in the number of conduction electrons. Adsorbed hydrogen on Pt–graphite is concluded to be positively polarized in molecular form.
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    Hydrogenation of Ethylene on Metal Electrodes: Part 2.—Structure of the Adsorption Layer on Platinum at a Working Condition on Open Circuit
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Fujikawa, Keikichi; Katayama, Akiko; Kita, Hideaki
    The structure of the adsorption layer was studied by the potential sweep method on a platinum electrode in 1 N HC104 solution saturated with a reaction gas of various compositions (mixtures of H2, C2H4 and He). Results show that the structure of the adsorption layer satisfies previous predictions on the rate-determining step and that the open circuit potential is determined by the equilibrium condition of the step, H++e_^H(ads). The large change in the hydrogen peak caused by standing the electrode in the solution is in agreement with the decay of the catalytic activity for the hydrogenation of ethylene.
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    Hydrogenation of Ethylene on Metal Electrodes: Part 2.—Structure of the Adsorption Layer on Platinum at a Working Condition on Open Circuit
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Fujikawa, Keikichi; Katayama, Akiko; Kita, Hideaki
    The structure of the adsorption layer was studied by the potential sweep method on a platinum electrode in 1 N HC104 solution saturated with a reaction gas of various compositions (mixtures of H2, C2H4 and He). Results show that the structure of the adsorption layer satisfies previous predictions on the rate-determining step and that the open circuit potential is determined by the equilibrium condition of the step, H++e_^H(ads). The large change in the hydrogen peak caused by standing the electrode in the solution is in agreement with the decay of the catalytic activity for the hydrogenation of ethylene.