不同硅铝比ZSM-5的合成及其吸附模拟柴油中的苯胺

Synthesis of ZSM-5 zeolite with different silica-alumina ratio and its adsorption removing aniline from model diesel

采用水热法合成了一系列具有不同硅铝比的ZSM-5分子筛。采用 XRD、ICP、SEM、IR、N2吸附脱附和NH3-TPD等对其进行了表征。结果表明,各样品均为具有典型 MFI结构的ZSM-5分子筛,不含杂质相,结晶度良好;各样品的实际硅铝比与体系加入的硅铝比相比均有所降低;样品晶体形貌清晰,而且在样品Z75中出现了雪花状的颗粒;Z75的孔容和平均孔径最大,但比表面积最小,其它样品的孔容、平均孔径和BET比表面积较接近;随着硅铝比的增加,酸量都有下降趋势。硅铝比较小的 Z25和Z50吸附脱除苯胺的效果均明显优于其他样品,Z50吸附苯胺符合准二级动力学方程。

A series of ZSM-5 zeolites were synthesized by hydrothermal adsorption-desorption and NH3-TPD. ZSM-5 zeolites have various particle size and different silica-alumina ratio. Results indicate that all have MFI structure and characteristic of ZSM-5 zeolite,which have no impurity phase and well crystallization,the crytal morphology of all samples is clear,the Z75 sample had some snowflake-shaped particles,the practical silica-alumina ratio of all samples decreased a little compare with that in synthesis system,the pore volume and avaerage pore size of Z75 are the biggest than others but the specific area is minimal. And pore volume,average area and BET surface area of other samples are similar to each other.Acid contant of all samples decilne with the increasement of silica-alumina ratio. The adsorption denitrification performance of Z25 and Z50 with low silica-alumina ratio is more superior to that of other three samplesand it is found that the pseudo-second-order kinetic model could provide better correlation with the experimental data of aniline.