Abstract
We have synthesized the pure single phase of aluminium tri-hydrogen bis (orthophosphate) monohydrate [AlH3(PO4)2·H2O] by using hydrophilic organic solvent, with high efficiency. It is a material with layered structure. The optimum condition to prepare it was as follows; the mixtures of 75wt% H3PO4 and Al(OH)3 (0.1mol) (molar ratio of H3PO4 to Al(OH)3=4.0) was refluxed at 94°C for 6 hours under stirring in 1-propanol (200cm3). Shape of products obtained was needle, and its length increased from 5μm to 80μm with increasing the reaction times. The maximal acid strength and amount of acid of solid surface were pKa=+1.5 and 1.81-2.13 (x10-2mmolg-1), respectively. AlH3(PO4)2·H2O changed to AlPO4 (berlinite, cristobalite-form) and Al(H2PO4)3 (B-form, C-form) by dehydration of monohydrate at 160°C.
