SYNTHESIS AND CHARACTERIZATION OF A NEW TYPE OF MESOPOROUS MOLECULAR SIEVE CaZr_4(PO_4)_6 BELONGING TO NZP FAMILY

Using cationic surfactant cetyltrimethyl ammonium bromide (CTAB) as template,a new type of mesoporous molecular sieve with the chemical composition of CaZr4(PO4)6,which belongs to NaZr2(PO4)3 (NZP) familyes,was successfully synthesized by inorganic sol-gel process with addition of organic acid. The synthesized powder materials were characterized by means of X-ray diffraction,N2 adsorption method and high resolution transmission electron microscope. The results show that a crystalline compound CaZr4(PO4)6 with mesoporous structure is obtained when the mole ratio of CTAB to ZrO2 is (0.6-0.8):1,and the synthesized CaZr4(PO4)6 has a specific surface area of 67-80 m2/g,a pore volume of 0.17-0.21 cm3/g and an average pore size of 8.5 nm. According to the above research results,it is promising to explore the application area of the powder with NZP family structure from traditional low thermal expansion ceramic to the innovative area of molecular sieve catalytic materials.