Fe-多级孔Hβ的制备及催化合成二苯甲烷性能

Preparation and Catalytic Benzylation Performance of Fe-hierarchical Porous Hβ

用NaOH溶液对Hβ进行处理,得到多级孔Hβ分子筛。在0.10 mol/L碱浓度下,采用浸渍法制备Fe-多级孔Hβ分子筛(Fe-Hβ-B0.10)。通过XRD、XRF、N2吸附-脱附、SEM-EDS、傅里叶变换红外光谱、NH3-TPD和Py-FTIR对样品进行了表征。结果表明,适当的碱浓度处理在保持Hβ分子筛微孔骨架的同时,引入了介孔,Fe-多级孔Hβ分子筛仍能保持微介孔结构,活性组分Fe2O3能够很好地分散在载体表面。以苯和氯化苄为原料,考察其催化合成二苯甲烷的性能。与Fe-Hβ-B0催化剂相比,Fe-多级孔Hβ有效地提高了反应物和产物的扩散性能,氯化苄的转化率、二苯甲烷的选择性分别提高了9.4%和3.2%。Fe-多级孔Hβ催化剂重复使用3次后仍然保持较好的催化活性。

Hierarchical porous Hβ molecular sieve was obtained by treating Hβ molecular sieve with NaOH solution. Fe-hierarchical porous Hβ molecular sieve was prepared by impregnation method in 0.10 mol/L alkali solution. The samples were characterized by XRD, XRF, N2 adsorption-desorption, SEM-EDS, FTIR,NH3-TPD and Py-FTIR. The results showed that proper alkali concentration treatment could not only maintain the microporous framework of Hβ molecular sieve, but also introduce mesopores. Fe-hierarchical porous Hβ molecular sieve also could maintain the micro-mesoporous structure, and the active component Fe2O3 could be well dispersed on the surface of the carrier. The catalytic synthesis of diphenylmethane from benzene and benzyl chloride was studied. Compared with Fe-Hβ-B0 catalyst, Fe-hierarchical porous Hβeffectively improved the diffusion performance of the reactants and products. The conversion of benzyl chloride and the selectivity of diphenylmethane were increased by 9.4% and 3.2%, respectively.Fe-hierarchical porous Hβ still maintained good catalytic activity after repeated use for 3 times.