Structural, Textural, and Catalytic Properties of Ti(IV)‐Fe(III) Mixed Oxides Prepared by a Modified Sol‐Gel Route

Abstract

Iron(III) titanates and Fe(III)‐modified titania were prepared via a modified sol‐gel method. Structures, texture and phase transformations after calcination at different temperatures were investigated. Fe(III) ions below 10 % were well dispersed in the titania lattice. Pseudorutile (Fe2Ti3O9) was prepared starting with a solution containing 40 % Fe(III) and calcining the product at 500 °C. Starting with equal concentrations of both metal ions resulted in a mixture of pseudorutile and pseudobrookite, Fe2TiO5. However, using 66.7 % Fe(III) to prepare pseudobrookite resulted in segregation of trace amounts of iron(III) oxide and rutile. All mixed oxides possessed significantly higher surface areas (178‐217 m2/g), larger pore volumes (0.16‐0.27 cc/g), and more homogeneous mesopores compared with the parent single metal oxides. Fe2TiO5 showed promising catalytic activity in the catalytic oxidation of toluene. A conversion of 100 % to CO2 was obtained at temperatures ≥300 °C and its catalytic activity correlates with its enhanced reducibility as studied by H2‐temperature programmed reduction (H2‐TPR).