Influence of pH and nature of the anion on the synthesis of pure and iron-containing mesoporous silica

Different salts are employed in the syntheses of pure and iron-containing m esoporous silica. Fluoride ions buffer the pH of the synthesis mixture and favour introduction of iron in the final product. Samples synthesized in ne utral conditions present thick pore walls and relatively low pore volume, w ith excellent stability upon activation. Extraction of surfactants upon was hing and shrinking of pore walls upon calcination are responsible for sever e modifications of the textural properties of samples synthesized in acidic conditions. (C) 2001 Elsevier Science B.V. All rights reserved.