Mitsuo Ueno

Electrocatalysis of transition-metal oxides for reduction and oxidation of nitrite ions

Abstract Electrodes of Mn, Fe, Co, Ni and Cu oxides supported on graphite substrates were prepared by pyrolysis of the metal nitrates. Ex situ X-ray photoelectron spectroscopy (XPS) revealed that Mn, Fe and Ni oxides at different chemical states were present at the electrode surfaces. The electrodes catalyzed the reduction and oxidation of NO 2 − in a weakly acidic medium (pH 2). All of the electrodes were deactivated by increasing the amount of metal oxide deposited, probably because of an increase in electric resistance of the deposited electrodes. The Fe oxide electrode with a small amount of deposited oxide exhibited the highest activity for the reduction and oxidation of NO 2 − .

A new method for evaluating the inner pore structure of porous catalysts—Resin replication of silica

In this note, the authors present SEM images of the shapes of a porous silica catalyst support observed by a new resin replication which had been successfully adopted for the visualization of pore structures of porous aluminum electrodes

Observation of ultra-fine palladium particles on a flat classy carbon electrode with a high resolution scanning electron microscope

Ultra-fine palladium particles (>2 nm diam.) which were well aged by electrochemical oxidation-reduction in an aqueous solution of HClO4 after being vacuum-evaporated on a flat plane of a glassy carbon electrode, have been observed by high resolution scanning electron microscopy (SEM).

Visualization of pore-structure of porous materials by computer graphics

Inner structure of porous inorganic materials has been visualized by a combined technique based on scanning electron microscopy and volume rendering method.

An Application of Tube‐Type Fibers to the Deposition of Small Au Particles onto Flat Si Substrates

A new technique to prepare small Au particles deposited onto flat Si substrates has been demonstrated using tube-type fibers of polyethylene telephthalate (PET) as the mask for vacuum evaporation of Au. Each of these fibers has a hollow of a unique size, wich can precisely control the particle size