Abstract
Since a preparation and catalytic activity of "Urushibara-Nickel" were published, some experimental efforts have been devoted by means of X-ray and electron diffraction techniques, but there is little publication indicating a unique relation between any physical or chemical properties of the Ni-fine particles and the catalytic activity, only similar behaviors to "Raney-Nickel" being reoorted.
The authors investigated the catalytic activity as a function of crystal (particle) size in the hydrogenation of acetone and various factors influencing the particle size in U-Ni-BA crystals, of which it has been reported that the catalytic activity of U-Ni-BA catalyst changes with the concentration of used Ni-chlorides.
As a result of the present experiment, it must be noted that ; (1) the cause of the cata-lytic activity can not be explained only by particle size, (2) in the U-Ni-BA crystals showing a remarkable activity, it was found from X-ray and electron diffraction analyses that "Hexagonal crystals" coexist in normal f.c.c. Ni-fine particles, and it was concluded also that the hexagonal crystals might be h.c.p. Ni included in f.c.c. Ni from the experimental result in which any possibility of existence of Ni-and Al-oxides, hydroxides and other substances was checked by the comparison of their X-ray patterns.
