Mesoporous silica-phosphate hybrids were successfully prepared by three processes: hybridization post synthesis by H 3 PO 4 , hybridizations during synthesis by Na 2 HPO 4 and by PO(OC 2 H 5 ). X-ray diffraction patterns confirm that the hexagonal pore structure was maintained after the hybridization process. The maximum phosphate amount was 2.9 mol % in the sample prepared by hybridization during synthesis from Na 2 SiO 3 and PO(OC 2 H 5 ) 3 . The specific surface area showed a large value of approximately 1000 m 2 /g despite the hybridization. The SiOP bonds were confirmed by nuclear magnetic resonance and X-ray photoelectron spectroscopy. The maximum adsorption amount of rare earth metal cations into the hybrid was approximately 70% of the initial concentration (50 mg/L) for each rare earth metal cation in coexistence with 13 rare earth metal cations.

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