THE ACTIVE PHASE (Ni2+) DISTRIBUTION IN Ni/γ-Al2O3 CATALYSTS PREPARED BY IMPREGNATION OF BIS(ETHYLENEDIAMINE)NICKEL(II) COMPLEXES

Abstract

Pore volume and wet impregnations were carried on γ-Al2O3 support spheres using [Ni(H2O)6](NO3)2 and [Ni(en)2(H2O)2]X2 complexes, where en = ethylenediamine and , Cl−, or CH3COO−. The distribution of nickel on the support was studied by optical microscopy and SEM-EDX. The use of ethylenediamine complexes leads to samples with nearly uniform profiles. The distribution is dependent on interaction of complexes with alumina, changes in viscosity during drying, and crystallization volume. Redistribution during drying is minimal for the ethylenediamine complexes. The study illustrates that increase in viscosity retards the convection distribution to outward migration. Cyclohexanol decomposition was studied as a test reaction and the results demonstrate that the macrodistribution of nickel oxide phase influences the product distribution.