Ionothermal synthesis of microporous aluminum and gallium phosphates

Four aluminum and gallium phosphates including AlPO4-quartz (1), GaPO4-quartz (2), AlPO4-LTA (3) and GaPO4-LTA (4) were ionothermally synthesized using [Emim]Br as structure-directing agent (SDA) and solvent. The samples were characterized by scanning electron micrographs (SEM), X-ray single crystal diffraction and X-ray powder diffraction (XRD). Effects of synthesis conditions, such as P2O5/Al2O3 and HF/Al2O3 ratios, as well as P2O5/Ga2O3 ratio and reaction temperature on the crystallization of aluminum and gallium phosphates were investigated, respectively. It was indicated that the P2O5/Al2O3 ratio or P2O5/Ga2O3 ratio played the dominant role in the phase transformation of aluminum phosphates or gallium phosphates.