The coordination changes of Co^(2+) in Y-zeolite prepared by ion-exchange and dehydrated at various temperatures, have been investigated by UV/VIS diffuse reflectance spectroscopy. Fully hydrated zeolites show an octahedral coordination of [Co(H₂)_6...
The coordination changes of Co^(2+) in Y-zeolite prepared by ion-exchange and dehydrated at various temperatures, have been investigated by UV/VIS diffuse reflectance spectroscopy. Fully hydrated zeolites show an octahedral coordination of [Co(H₂)_6]^(2+) in the supercage with some interaction with the framework. During dehydration at high temperatures, Co^(2+) in Yzeolite changes its coordination, first from a symmetric to distorted tetrahedral and, successively, to an octahedral coordination. Fully hydrated sample of impregnated cobalt nitrate in Y-zeolite shows an octahedral coordination of Co(H₂O)_6(NO₃)₂. During dehydration at high temperature, the cobaltous nitrate decomposes to the cobalt oxide. However, the small amount of cobalt ions in cobaltnitrate are ion-exchanged simultaneously.