The influence of microwave-assisted synthesis on nanocrystalline iron silicalite-1 particles

Abstract

The influence of microwave synthesis conditions (time, temperature) and aging of clear solutions on the size, morphology, iron content, and aggregation of nanocrystalline particles were studied for iron silicalite-1 (FeS-1). The compound crystallized from a starting clear solution (10TEOS : 0.2FeCl₃ : 3TPAOH : 245H₂O) using one- and two-step microwave-assisted hydrothermal syntheses. The smallest round FeS-1 intergrown crystals with a mean diameter of 300 nm composed of 40 nm particles were obtained by two-step microwave-assisted hydrothermal syntheses. The study of iron local structure in FeS-1 by using UV-Vis and Mössbauer spectroscopy revealed the presence of framework and extra-framework iron species. A reaction of N₂O decomposition to N₂ and O₂ was used as a test to confirm higher catalytic activity of smaller crystallite size.