Physicochemical Characterization of Isomorphously Substituted FeZSM-5 during Activation

Physicochemical characteristics of isomorphously substituted FeZSM-5 both after preparation and after activation have been determined by gas (Ar and N2) physisorption, 27Al and 29Si magic-angle spinning–nuclear magnetic resonance, NH3 temperature-programmed desorption, transmission electron microscopy, H2 temperature-programmed reduction (TPR), 57Fe Mossbauer spectroscopy, and voltammetric response techniques. The activation of as-synthesized FeZSM-5 comprises calcination at 823 K and a subsequent steam treatment (300 mbar of H2O in N2) at 873 K. Calcination leads to complete removal of the template. During this process a significant fraction of iron is dislodged to extraframework positions…