不同方法合成Y沸石包覆Ru金属催化剂及其性能研究

Synthesis and Properties of Y Zeolite‐Encapsulated Ru Metal Catalyst via Different Methods

采用原位水热法、离子交换法、浸渍法制备了系列Y沸石包覆Ru金属催化剂,讨论了采用原位水热法合成过程中Ru金属的添加顺序及不同合成方法对沸石物性及催化性能的影响;采用XRD、XRF和SEM等方法表征了沸石的组成和结构性质;采用H_(2)‐TPR、H_(2)‐TPD、TEM、CO‐IR和XPS等表征方法表征了沸石中Ru金属的存在状态;采用NH_(3)‐TPD和Py‐IR表征了沸石的酸性质。结果表明,Ru金属的添加顺序对原位水热法合成的沸石影响较小;原位水热法合成的沸石包覆金属效果最好;在异丁烷异构化制正丁烷的反应中,所得Ru@HY‐Si具有最高的异丁烷转化率及正丁烷选择性,在反应温度为673 K、质量空速为4 h^(-1)时催化活性最佳。

A series of Y zeolite‐encapsulated Ru metal catalysts were prepared by the in‐situ hydrothermal method,ion exchange method,and impregnation method.The effects of the Ru metal introduction sequence during the in‐situ hydrothermal synthesis process and the synthesis methods on the physical properties and catalytic performance were discussed.Methods including XRD,XRF,and SEM were used to characterize the composition and structure of samples,and the presence states of Ru metal in zeolite were characterized by H_(2)‐TPR,H_(2)‐TPD,TEM,CO‐IR,and XPS.The acidity properties of the samples were characterized by NH_(3)‐TPD and Py‐IR.The results indicate that the addition order of Ru metal has little effect on the zeolite synthesized by the insitu hydrothermal method,and this method is the best choice for Ru metal encapsulation.For the isomerization of isobutane to n‐butane,the prepared Ru@HY‐Si exhibits the highest isobutane conversion and n‐butane selectivity and optimal catalytic activity at 673 K with a mass space velocity of 4 h^(-1).