Hydrogen Reduction of a Single Crystal of Nickel Oxide

Abstract

Abstract In the hydrogen reduction of a single crystal of nickel oxide, the rate of reduction does not always increase with an increase in the reduction temperature. In the range of 350 to 500°C the rate decreases with the temperature, and the rate is the lowest at 500°C. These facts are explained reasonably by the microscopical examination of the surface of the reduced nickel. It is concluded that the desorption of the water formed through the pores is a rate-determining step in the reduction of the single crystal of nickel oxide. The nickel formed on (100) plane of nickel oxide by the reduction has (100) plane as a preferential orientation.