Effect of template content on the physicochemical characterization and catalytic performance of SAPO-11 for the hydroisomerization of n-tetradecane

Different SAPO-11 have been synthesized hydrothermally using the mixed template of di-n-propylamine (DPA) and di-iso-propylamine (DIPA) by varying the template content or the ratio of DPA/DIPA. Products were characterized using X-ray diffraction (XRD), N2 adsorption, NH3temperatureprogramed desorption (TPD) and 29Si MAS NMR, and evaluated towards n-tetradecane skeletal isomerization. The results indicated that the template had strong influence on the crystallinity, the Si distribution and thus the acidity of SAPO11. The sample prepared at template content of 1.5 and w (DPA) of 66% possessed small silicon domains and large amount of Si(n Al)(0 < n < 4) sites, and the catalyst obtained with this method performed highest catalytic activity in the hydroisomerization of n-tetradecane due to the high acidity.