摘要
采用干凝胶法原位合成出颗粒粒径约为50~120 nm且含骨架杂原子的超细Fe-ZSM-5分子筛,利用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、紫外-可见光光谱仪(UV-Vis)、氨的程序升温脱附(NH3-TPD)、吡啶吸附红外光谱(Py-FT-IR)和N2吸附-脱附等手段对样品进行表征。结果表明:原位添加的Fe源不仅可以降低分子筛颗粒粒径,还能降低分子筛酸强度;原位合成的Fe-ZSM-5分子筛中Fe物种主要以四配位骨架Fe3+存在,其余以低聚的FeOx以及Fe2O3颗粒存在,而浸渍法制备的Fe/ZSM-5分子筛中Fe物种主要以后2种形式存在;Fe改性调变了ZSM-5分子筛的酸性质,从而提高了MTP反应产物丙烯的选择性;与负载型Fe/ZSM-5分子筛催化剂相比,原位改性的含骨架杂原子超细Fe-ZSM-5分子筛催化剂由于具有更小的晶粒粒径和适宜的酸性质,从而进一步提高了丙烯选择性。
Ultrafine Fe-ZSM-5 zeolite containing framework heteroatoms with around 50-120 nm in diameter was successfully in-situ synthesized via a dry gel conversion method.The fabricated samples were characterized by means of XRD,SEM,TEM,UV-Vis,NH3-TPD,Py-FT-IR and N2 adsorption-desorption isotherms.The results indicate that Fe source added in-situ can not only reduce the size of zeolite particles,but also reduce the acid strength of zeolite.Ultrafine Fe-ZSM-5 zeolite prepared by in-situ synthesis method contains three kinds of Fe species,and most of Fe attributes to isolated framework Fe^(3+)species in tetrahedral coordination and the rest exists as oligomerized FeOx and Fe2O3 particles.But Fe/ZSM-5 zeolite pre-pared by impregnation method mainly contains latter two forms of Fe species with a little of Fe3+in the framework of the zeo-lite.The acid properties of ZSM-5 zeolite were modified by Fe modification,which improved the selectivity of propylene in MTP reaction.Compared to the Fe/ZSM-5 zeolite fabricated by traditional impregnation method,the in-situ synthesized ul-trafine Fe-ZSM-5 zeolite containing framework heteroatoms presents higher propylene selectivity in the MTP process due to smaller grain size and more suitable acid properties.
作者
王有和
李晨灿
代畅
臧金龙
杜宁宁
毛雨馨
阎子峰
WANG Youhe;LI Chencan;DAI Chang;ZANG Jinlong;DU Ningning;MAO Yuxin;YAN Zifeng(State Key Laboratory for Heavy Oil Processing in China University of Petroleum(East China),Qingdao 266580,China;Shandong High-End Chemical Research Institute,Heze 274002,China)
出处
《中国石油大学学报(自然科学版)》
EI
CAS
CSCD
北大核心
2023年第6期178-184,共7页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家自然科学基金项目(21776311)
中央高校基本科研业务费专项(22CX03001A)
山东省自然科学基金项目(ZR2023MB101)
山东省泰山学者攀登计划项目(tspd20210308)
大学生创新创业训练项目(S202110425026)。
