Abstract: In the eutectic mixtures of pentaerythritol and tetraethylammonium chloride，SAPO-34 molecular sieves were successfully synthesized in--situ on Suzhou kaolin microspheres.The effects of synthesis conditions and composition of the crystalli-zation liquid on the crystallization of SAPO-34 molecular sieves were investigated.The synthesized microspheres were characterized by XRD and SEM etc..SAPO-34 molecular sieve microspheres were synthesized optimally at 180 ℃ for 20 h using the gel composition at n（SiO2）∶n（Al2O3）∶n（P2O5）∶n（SDA）∶n（HF）∶n（H2O）=2.26∶1∶0.5∶0.66∶0.3∶26.4. N-methylimidazole and 2-methylimidazole were the favorable SDAs（structure directing agents） for the synthesis of SAPO-34 molecular sieves  ionothermally.

Key words: SAPO-34 molecular sieve, in-situ synthesis, Ionothermal synthesis, kaolin microspheres