多级孔 Hβ分子筛的制备及醚化性能研究

摘要

The hierarchical porous Hβ zeolite with BEA structure was prepared by alkaline treating Hβ zeolite with NaOH solution. The zeolites before and after treatment were characterized by XRD, SEM,N2 adsorption-desorption,NH3-TPD and Py-FTIR. The FCC light gasoline etherification was in-vestigated in a fixed bed reactor. The results show that alkali treatment can change pore structure and adjust the amount and distribution of acdic sites effectively. As the alkalinity of NaOH solution increa-ses,part of the microporous structure is destroyed,mesopore and acidity increases. At proper alkalini-ty,with increasing treatment temperature and time,the specific surface area and acid of the Hβ zeolite decrease. At conditions of 0.2 mol/L NaOH solution,60 ℃,0.5 h,the micropore structure of the zeo-lite can be preserved to a maximum extent while the mesopore is formed. The Hβ zeolite treated at this condition has the best catalytic activity.%用 NaOH 溶液对 Hβ分子筛进行碱处理，得到了含有多级孔的 BEA 结构分子筛，并采用 XRD、SEM、N2吸附-脱附、NH3-TPD、Py-FTIR 等方法对处理前后的分子筛进行表征，在固定床反应器上进行了催化裂化轻汽油醚化反应的研究。结果表明：通过改变处理条件可有效调变 Hβ分子筛的孔道结构及酸量分布；随着 NaOH 溶液浓度的提高，Hβ分子筛微孔结构破坏严重，介孔数量增多，同时酸量增加；当 NaOH 溶液浓度一定时，随着处理温度和处理时间的增加，微孔比表面积下降，酸量下降；在处理条件为 NaOH 浓度0.2 mol/L、处理温度60℃、处理时间0.5 h 时，Hβ分子筛可在最大程度上保持微孔结构的同时生成介孔，且适宜醚化反应的B 酸量适中，该分子筛催化活性最高。