EFFECT OF Ni ATOMIC PERCENT ON Ni DISPERSION AND CATALYTIC ACTIVITY IN PREPARATION OF CATALYSTS FROM La-Ni INTERMETALLIC COMPOUNDS

Abstract

A previous study showed that oxidation of LaNi₅ could produce catalysts with a relatively high Ni dispersion.
This study focuses on the effect of Ni atomic percent α upon Ni dispersion δ and turnover frequency TF, using La-Ni compounds. It was found that the value of δ was higher in the order of LaNi₅ >La₂Ni₇ >LaNi³ > LaNi and that this order was related to oxidation rate. The value of TF, on the other hand, was higher in the reverse order, indicating that high oxidation rate causes severe defects on the surface of Ni crystallites.