|
-CLO |
Cloverite (GaPO4) |
P(50), Ga(50) |
Contributed by Céline Schott-Darie
Verified by S. Bradley, by W. Schmidt, and by R Fricke
Type Materials 8{[Ga96P96O372(OH)24(QF)24( H2O)n} (Q = quinuclidine [1])
Method A. Merrouche, J. Patarin, H. Kessler, M. Soulard, L Delmotte, J.-L Guth, J. F. Joly [2]
Batch Composition Ga2O3 : P2O5 : HF : 80 H2O : 6 Qa
Source Materials
phosphoric acid (Fluka, 85% H3PO4)
distilled water
gallium sulfate [Ga2(SO4)3. xH2O] (Strem Chemicals, wt.% Ga ~18) b
hydrofluoric acid (Fluka, 40% HF)
quinuclidine (Fluka, 97% C7H13N)
Batch Preparation (for 1 g product)
(1) 10.95 g phosphoric acid + 2.2 g H2O + 3.14 g gallium sulfate hydrate + 2.2 g H2O] stir until dissolved
(2) [(1) + 0.2 g HF + 2.7 g qumucidine], mix until uniform. Initial pH = 4 to 4.5
Crystallization
Vessel: PTFE-lined autoclave
Temperature: 1500C
Time: 24 hours
Agitation: none
Product Recovery
(1) Filter, wash with distilled water, dry at 600C
(2) Yield: approximately 60% on Ga2O3 and P2O5
Product Characterization
XRD: Characteristic strong reflections at d 25.4, 9.1 and 8.5 Å; competing phases are GaPO4-a and GaPO4-b [2] when the starting molar ratio F/Ga2O3 <0.5 [3]
Elemental Analysis (anhydrous form): Q0.14Ga0.48P0.52O2F0.13
Crystal Size and Habit: small cubes, less than 1 um c
Click here to view XRD pattern
References
[1] M. Estermann, L B. McCusker, C. Baerlocher, A. Merrouche, H. Kessler, Nature 352 (1991) 320
[2] A. Merrouche, J. Patarin, H. Kessler, M. Soulard, L Delmotte, J.-L Guth, J. F. Joly, Zeolites 12 (1992) 226
[3] J. Patarin, C. Schott-Darie, A. Merrouche, H. Kessler, M. Soulard, L Delmotte, J.-L Guth and J. F. Joly in Proceedings from the 9th International Zeolite Conference, R. von Ballmoos, J. B. Higgins and M. J. Treacy (eds), Butterworth-Heinemann, Stoneham, 1992, p. 263
Notes
a. The acceptable range for HF/Ga2O3 is 0.75 to 2.
b. Aldrich Ga2(SO4)3 acceptable substitute.
c. Crystals are typically cubes with apparent truncatures when large (20 um or more). Increase in crystal size has been achieved by decreasing the amount of fluoride in the starting mixture to F/Ga2O3 <0.5 [3].