低温晶化对B-ZSM-5和Ti-ZSM-5物化性能的影响

 以改进方法合成的B-ZSM-5分子筛为母体,采用气固相法合成了Ti-ZSM-5分子筛,并以XRD,FT-IR,UV-Vis,XRF,SEM,ICP-AES和MAS NMR等手段对B-ZSM-5和Ti-ZSM-5进行了表征,考察了Ti-ZSM-5对苯酚羟基化反应的催化性能. 结果表明,合成B-ZSM-5时的前期低温晶化有助于晶粒的减小; 以其为母体制备的Ti-ZSM-5对苯酚羟基化反应具有优异的催化性能. 在n(PhOH)/n(H2O2)=3,n(Me2CO)/n(PhOH)=2.7,m(cat)/m(PhOH)=5%,T=353 K和t=6 h的反应条件下,苯酚转化率可达20%以上.

Effect of Low-Temperature Crystallization on Physico-Chemical Properties of B-ZSM-5 and Ti-ZSM-5

The Ti-ZSM-5 zeolite samples were successfully synthesized via gas-solid method with B-ZSM-5 zeolite prepared by modified hydrothermal synthesis as precursor. The samples were characterized by XRD, FT-IR, UV-Vis, XRF, SEM, ICP-AES and MAS NMR, and their catalytic performance for hydroxylation of phenol was investigated. The results showed that the crystallization at lower temperature during the synthesis of B-ZSM-5 was advantageous to get smaller crystal size and the Ti-ZSM-5 samples prepared by using B-ZSM-5 with smaller crystal size as precursor showed better performance for hydroxylation of phenol. Under the reaction conditions of n(PhOH) / n(H_2O_2) =3, n(Me_2CO) / n(PhOH) =2.7, m(cat) / m(PhOH) =5%, T=353 K and t=6 h, the phenol conversion was over 20%.