MCM-48 mesoporous molecular sieves containing iron(III) were obtained
using a direct sol-gel route followed by removal of the cetyltrimethyl
ammonium hydroxide template before calcination. UV-visible, ESR, and X
ANES spectroscopies show that iron mostly occupies tetrahedral sites o
f the siliceous walls. The formation of oxide nanoclusters in the chan
nels is favored in the presence of the organic template molecules duri
ng calcination.