Abstract
Nickel/alumina catalysts were prepared by the deposition of nickel chloride vapor on spherical alumina (3.5 mm diameter) followed by reduction. This paper describes the effects of preparation conditions (deposition time and deposition temperature) on the nickel content, the nickel concentration profile, and the nickel particle diameter.
The nickel content increased with increasing deposition time of nickel chloride vapor, and decreased with increasing deposition temperature. The average nickel particle diameters were observed by TEM, and were not affected substantially by deposition time or deposition temperature. They ranged from 500 to 650 nm. The intraparticle penetration of nickel proceeded with increasing deposition time. The activation energy of acetylene hydrogenation was about 50 kJ·mol–1, regardless of the preparation method, which involves gas phase method and impregnation method. The activity per unit surface area of nickel showed the following order: vapor deposition nickel/alumina > gas phase reduction nickel ≅ impregnated nickel/alumina.
