多级孔硅沸石负载金催化乙炔氢氯化的研究

Study on the catalytic performance of hierarchical silicalite-1 supported gold for acetylene hydrochlorination

采用水热合成法和混合碱液后处理法分别制备了具有无孔、微孔和微-介孔的三种硅沸石载体,本文考察了不同孔径载体负载金催化剂在乙炔氢氯化合成氯乙烯中的催化活性和稳定性。采用X射线粉末衍射仪(XRD)、红外光谱仪(IR)和物理吸附仪表征了三种载体的结构特性,透射电子显微镜(TEM)、氨气/二氧化氮-程序升温脱附(NH_(3)/CO_(2)-TPD)分析了催化剂表面金粒子尺寸和表面酸碱特性,结合催化剂的活性和积碳量,发现微-介孔的硅沸石作为载体更有利于抑制催化剂上金粒子的移动、聚集和改善反应传质效率,显著提升催化剂的乙炔氢氯化活性和稳定性。

Silicalite-1 support with non-porous,microporous and micro-mesoporous were prepared by hydrothermal synthesis method and mixed alkali post-treatment method,respectively.The catalytic activity and stability of gold catalysts supported on silicalite-1 with different pore sizes in the synthesis of vinyl chloride by acetylene hydrochlorination were investigated.The structural characteristics of silicalite-1 were characterized by XRD,IR and physical adsorption instrument.The gold particle sizes and surface acid-base properties of the catalyst surface were analyzed by TEM and NH_(3)/CO_(2)-TPD.Combined with the activity and carbon deposition of the catalysts,it was found that the micro-mesoporous silicalite-1 as the support was beneficial to inhibit the movement and aggregation of gold particles on the catalyst and improve the reaction mass transfer efficiency,thereby significantly improving the acetylene hydrochlorination activity and stability of the catalyst.