Papers by Author: Hiroaki Hatori

Abstract: The effect of surface modification by nanoparticles of metal compounds was investigated by means of gas and vapor adsorption analysis. The surface of activated carbon fiber cloths was modified by loading of Li2CO3 and MgO nanoparticles. The particles on the carbon surface played as initial adsorption site of water molecules, leading to the promotion of micropore filling without diminishing the micropore volume of the porous carbon supports. The increasing characteristic adsorption energy suggested some interaction between methane molecules and the particles.

Abstract: Three-dimensional (3D) observation of Pt nanoparticles on the surface of carbon nanoparticles, one of the important catalyst systems for energy storage such as fuel cells, was carried out by using an electron tomography system attached to a transmission electron microscope (TEM). In the Pt/carbon sample preparation process, pristine and graphitized carbon nanospheres (CNSs, 200 nm average diameter) were immersed into H2PtCl6 solution, followed by a heat-treatment at 493 K. According to the electron tomography technique, we confirmed that crystalline Pt particles (2-3 nm) were homogeneously dispersed on the whole surface of pristine CNSs, while on the graphitized CNSs Pt was aggregated on the ridgeline of the polyhedronized CNS particles or on the connecting surface between two CNS particles. Dependence of Pt dispersion as shown was discussed with the distribution of surface defects of CNS particles.