不同硅铝比ZSM-5的合成及其吸附脱除柴油中苯胺和吡啶的性能

合成了一系列不同硅铝比的ZSM-5分子筛,采用XRD、FT-IR、ICP、SEM、NH_3-TPD和N_2吸附-脱附等方法对其进行了表征,研究了不同硅铝比ZSM-5分子筛对模拟柴油中苯胺和吡啶的吸附脱除性能。结果表明,所合成的ZSM-5分子筛均具有典型MFI结构;与合成原料混合物中的硅铝比相比,实际硅铝比稍有降低。ZSM-5分子筛的酸量随硅铝比的增加而降低,硅铝比较小的ZSM-5(1)和ZSM-5(2)的吸附脱除苯胺或吡啶的效果明显优于其他样品,并且所有样品吸附脱除吡啶的效果均优于苯胺。ZSM-5(2)上苯胺和吡啶的吸附等温线符合Langmuir-Freundlich混合模型。

Synthesis of ZSM-5 zeolites with different silica/alumina ratios and their performance in the removal of aniline and pyridine from model fuel through adsorption

A series of ZSM-5 zeolites with different silica/alumina ratios were synthesized and characterized by means of XRD, FT-IR, ICP, SEM, NH₃-TPD and N₂ sorption; their performance in the removal of aniline and pyridine from a model fuel through adsorption was then investigated. The results indicated that all the as-synthesized ZSM-5 zeolites have the MFI structure, although the actual silica/alumina ratio in the as-synthesized ZSM-5 zeolites is somewhat lower than that in the corresponding synthesis mixture. As expected, the acid amount of ZSM-5 zeolites decreases with the increase of the silica/alumina ratio. The adsorption denitrogenation performance of ZSM-5(1) and ZSM-5(2) with relatively lower silica/alumina ratios is superior to that of other two zeolite samples; meanwhile, the removal efficiency for pyridine over all ZSM-5 samples is higher than that for aniline. Moreover, adsorption isotherms of aniline and pyridine over ZSM-5(2) accord with the Langmuir-Freundlich adsorption model.