I was successful at the first attempt to synthesize but then with excessive washing, it appears I decomposed it. Further attempts at synthesizing have been less fruitful and I am unsure if there is something I'm missing. I used this recipe: H3TATB (50 mg) and AlCl3 6H2O (200 mg) were dissolved in 10 ml DEF or DMF, then 1.0 ml trifluoroacetic acid was added. The mixture was heated up at 135 °C in an oven for 2 days until white precipitate formed. The white precipitate was centrifuged and washed with fresh DMF for several times. 

Then before BET measurements: The precipitate was washed twice with fresh DMF and then three times by acetone.

Any suggestions would be great!