Preparation of EG/Na X zeolite composite and its adsorptive properties on benzene gas

Zeolite was synthesized on the surface and interior pores of expanded graphite (EG) by hydrothermal method and a new EG/Na-X zeolite composite was prepared. The effect of SiO₂/Al₂O₃ molar ratio on the types of zeolite was investigated. Microstructures of the composite were characterized using XRD, FE-SEM, FTIR and N₂ adsorption-desorption techniques. The static desiccator method was used for adsorption capacity measurement. The results indicate that the types of zeolite are dependent on SiO₂/Al₂O₃ molar ratio. With the increase of SiO₂/Al₂O₃ molar ratio, types of zeolite transform from Na-A to Na-X gradually and transform completely when the SiO₂/Al₂O₃ molar ratio is 7.9. Adsorption datas show that static adsorption capacity of the composite for benzene gas can reach 340 mg/g at the temperature of 25 ℃.