THE INFLUENCE OF PREPARATION VARIABLES ON Ni CRYSTALLITE SIZE IN HIGH TEMPERATURE OXIDATION OF LaNi₅ ACCOMPANIED BY AN INCREASE IN SURFACE AREA

Abstract

In this study, the effect on crystallite size of oxidation temperature, oxidation time, and reduction temperature was investigated by the LaM₅ method to clarify the factors controlling catalytic properties. When nickel was oxidized, the increase in surface area due to powdering was considerable.
A model of the surface area increase was proposed based upon a shrinking-core model. An increase in the oxidation and reduction temperatures was accompanied by an increase in crystallite size.