AEI

AlPO4-18

Al(50), P(50)

Contributed by Rune Wendelbo

Verified by S. Kaliaguine, by E. Dumitnu, and by C. Round

Type Material [Al24P24O96]

Method S. T. Wilson, E. M.Flanigen [1, 2]

Batch Composition Al2O3: P2O5: (TEA)2O: 60 H2O : 6 i-C3H7OH (TEA = tetraethylanimonium)

Source Materials
distilled water
phosphoric acid (85%)
aluminum isopropoxide (Jansen, 98+ %)
tetraethylammonium hydroxide (Aldrich, 40% (TEAOH)a

Batch Preparation (for 15.8 g dry product)

(1) [36.3 g water + 15.0 g phosphoric acid + 27.2 g aluminum isopropoxide], add diluted phosphoric acid to the aluminum isopropoxide in a 250 mL polypropylene bottle and shake vigorously for one minute
(2) [(1) + 49 g (TEAOH solution], shake to produce a uniform gel. Transfer to the autoclave

Crystallization
Vessel: 200 mL Teflon-lined stainless steel autoclave (Berghof)
Incubation: 6 hours at room temperature
Time: 69 hours b
Temperature: 2150C b
Agitation: gentle c

Product Recovery
(1) Recover solid product by centrifugation d
(2) Wash once with distilled water; recover product by centrifugation d
(3) Dry overnight at 1000C
(4) Calcine for 4 h at 5500C in flowing dry air
(5) Store under nitrogen. Yield near 100%

Product Characterization
XRD: fully crystalline AEI; competing phase: AFI e
Elemental Analysis: 24.26% Al, 20.59% P, 0.20% Si f
Crystal size and habit: square platelets 0.2-8 um x 0.1 um thick g
Click here to view XRD pattern

References
[1] S. T. Wilson, E. M. Flanigen, US Patent 4310440 (1982)
[2] R Wendelbo, D. Akporiaye, A. Andersen, I. M. Dahl, H. B. Mostad, Appl. Catal. A General 142 (1996) L197

Notes
a. This product is now traded as 35% TEAOH solution. I would use the same volume of the 35% solution, since the synthesis is not sensitive to a variation of the template concentration of this order. It is important that the (TEA)OH source have minimum K+ and Na+ concentrations.
b. The synthesis temperature can probably be reduced to 2000C and the time reduced substantially, but this has not been tested.
c. Standing autoclaves in a heated block on a "shaking table" rotated at about 60 rpm.
d. Filtration leads to loss of fine material or goes very slowly depending on the filter.
e. AFI appears as a contaminant.
f. A Cameca microprobe was used averaging 5 points each 50 x 50 um. The analysis was done on "as synthesized material".
g. Micropore volume 0.28 mL/g (by N2 adsorption).