Zn改性纳米ZSM-5分子筛的物化性能及催化甲醇制汽油反应性能研究  

Study on the Physicochemical Properties and Catalytic Performance of Zn Modified Nano-ZSM-5 Zeolite for Methanol to Gasoline

作　　者：孟锦滢 张克 冯超群 白雪峰[1] 吴伟[1] MENG Jin-ying;ZHANG Ke;FENG Chao-qun;BAI Xue-feng;WU Wei(College of Chemical and Materials,Heilongjiang University,International Joint Research Center for Catalytic Technology,Harbin 150080,China)

机构地区：[1]黑龙江大学化学化工与材料学院催化技术国际联合研究中心,黑龙江哈尔滨150080

出　　处：《化学与粘合》2020年第3期153-158,187,共7页Chemistry and Adhesion

基　　金：国家自然科学基金(编号:21676074);黑龙江大学大学生A类创新训练项目(编号:2019062)。

摘　　要：以晶种引导法合成的纳米ZSM-5分子筛为母体,采用液相沉积法制备了系列不同Zn担载量的改性纳米ZSM-5分子筛催化剂,分别采用SEM、N2物理吸附、H2-TPR、NH3-TPD和Py-IR等手段对催化剂进行了表征,并考察了Zn改性前后的ZSM-5分子筛的物化性质及用于甲醇制汽油(MTG)的催化反应性能。结果表明,随着Zn担载量的增大,改性分子筛的孔容和比表面积减小,由Brφnsted酸提供的强酸位的强度减弱、强酸量减少,由Lewis酸提供的弱酸位的酸量减少、中强酸性位的强度增强、酸量增加,由Zn活性物种形成了新的更强的酸性位。ZnO担载量为2.0%(wt)的改性纳米ZSM-5分子筛2.0ZnNZ5是最适宜的MTG反应催化剂,当甲醇转化率为98.2%时汽油的选择性高达64.7%。A series of modified nano-ZSM-5 zeolite catalysts with different Zn loadings are prepared by liquid deposition method with the nano-ZSM-5 zeolite as matrix which is synthesized by seed crystal-induced method.The catalysts are characterized by means of SEM,N2 physical adsorption,H2-TPR,NH3-TPD and Py-IR technology.The physicochemical properties of the ZSM-5 and Zn modified zeolite and their catalytic performance in the process of methanol to gasoline(MTG)reaction are investigated.The results show that the pore volume and specific surface area of the modified zeolites decreases,the acid strength of the strong acid site provided by Brφnsted acid becomes weak and the density decreases,the acidity of the medium acid site provided by Lewis acid enhances and the density increases,while the density of the weak acid site decreases with the increase of Zn loading.The new stronger acid sites forms from Zn active species.The modified nano-ZSM-5 zeolite with 2.0%(wt)ZnO loading(2.0 ZnNZ5)is a more suitable catalyst for MTG reaction.A selectivity of 64.7%for gasoline achieves when the the methanol conversion is 98.2%.

关 键 词：纳米HZSM-5分子筛 液相沉积 Zn改性 甲醇制汽油(MTG) 

分 类 号：TQ426[化学工程]