Type Material Na_0.3(TPA)_3.7[Fe₄Si₉₂O₁₉₂] wH₂O (TPA = tetra-n-propylammonium)

Method A. Brückner, R. Lück, W. Wieker, B. Fahlke [1]

Batch Composition 30 Na₂O : Fe₂O₃ : 30 SiO₂ : 1040 H₂O : 5 (TPA)Br : 25 H₂SO₄

distilled water
sulfuric acid (reagent grade, 98% H₂SO₄)
iron(III) sulfate (reagent grade, Fe₂(S0₄)₃. 9 H₂O)
sodium metasiicate (reagent grade, Na₂SiO₃. 9 H₂O) ^a
tetrapropylammonium bromide (TPABr) (Fluka, CH-9470 Buchs)

Batch Preparation (for ~20 g volatile-free product)

(1) [100 g water + 22 g sulfuric acid + 5.62 g iron(III) sulfate], stir until dissolved
(2) [163.4 g water + 85.26 g sodium metasiicate], stir until dissolved
(3) [(1) + (2)], add silicate slowly to iron(III) sulfate solution with good mixing
(4) [(3) + 13.31 g TPABr], mix vigorously until uniform (~ 400 rpm)

Vessel: stainless steel autoclaves
Temperature: 170⁰C
Time: 72 hours
Agitation: autoclaves are rotated axially

(1) After cooling, filter and wash with water several times
(2) Dry over P₄0₁₀
(3) Calcine at 550⁰C for 4 hours to remove template

[1] A. Brückner, R. Lück, W. Wieker, B. Fahlke, Zeolites 12 (1992) 380

a. Al(III), a common impurity in silica sources, displaces Fe(III) from T-atom positions in MFI. [1]