拟薄水铝石物性对载体和Pd-Ag/Al2O3催化剂的结构及乙炔加氢性能的影响OA

To investigate the effects of support raw materials on the properties of supports and catalytic activities of catalysts for acetylene selective hydrogenation,pseudo-boehmite powders prepared by different manufacturing processes were made into supports by extrusion molding,which were then used to prepare supported Pd-Ag/Al2O3 catalysts.The pseudo-boehmite,supports,and catalysts were characterized by XRD,TG,SEM,TEM,H2-TPR,and XPS.The catalytic activities of the catalysts were evaluated in acetylene selective hydrogenation.The experimental results show that the support prepared from macroporous pseudo-boehmite powder produced by the double-aluminum method exhibits a lower bulk density,a large number of pores with diameters greater than 200 nm,and a higher proportion of the θ-Al2O3 phase.These features are favorable for dispersing and anchoring active species to form active sites with a moderate acetylene adsorption strength.Compared with the catalysts prepared from the other two pseudo-boehmite powders,Cat2,prepared with the aforementioned support,shows higher selectivity at the same conversion level,reducing the acetylene content in the reactor inlet stream to less than 5 μL/L.Under the same loading volume,Cat2 requires a less loading weight and a lower precious metal loading,significantly reducing catalyst cost while improving catalytic activity.