ironzeolite

Ironzeolites refer to zeolite materials in which iron is incorporated into the crystalline aluminosilicate framework or introduced as iron species within the pores. Iron can substitute for framework atoms or exist as isolated Fe3+ centers, small clusters, or nano-sized oxides inside the channels. The presence of redox-active iron endows these materials with catalytic and oxidative capabilities not found in many other zeolites.

Common families include Fe-ZSM-5, Fe-BEA, and Fe-FER. Synthesis typically uses hydrothermal crystallization in the presence of iron precursors or post-synthesis ion exchange, followed by calcination. The resulting iron speciation ranges from framework-substituted Fe3+ to extra-framework iron oxides, depending on synthesis conditions and aging.

Characterization relies on X-ray diffraction to confirm structure, UV-Vis and Mossbauer spectroscopy for iron speciation, and EPR for electronic environment. These materials usually exhibit high surface area and retained porosity, with acidity influenced by iron content.

Applications are dominated by catalysis. Iron-zeolites are widely studied for selective catalytic reduction of NOx with ammonia (NH3-SCR) and for oxidation of VOCs and light hydrocarbons at moderate temperatures. They are also explored for Fenton-like oxidation in water treatment and for certain biomass conversion reactions. Challenges include potential iron leaching under acidic conditions and sensitivity of active sites to hydrothermal aging, as well as reproducibility across preparations.

Ironzeolites illustrate the integration of redox-active metals with microporous frameworks to enable multifunctional catalytic performance.