Hierarchical SAPO-11 Molecular Sieves Prepared with the Presence of Designedly Phosphorylated Poly(Vinyl Alcohol)s

The purpose of this paper is to report an efficient templating synthesis of hierarchically porous SAPO-11 molecular sieves. Poly(vinyl alcohol) was phosphorylated to get different phosphorus contents, and those designedly modified polymers were employed as mesoporous template in the hydrothermal synthesis of SAPO-11. Consequently, the prepared hierarchical molecular sieves exhibited higher BET areas, regular mesopore structures, and better acidity than their conventional counterpart. The catalysts with SAPO-11s as support had improved catalytic conversion and selectivity in hydroisomerization of n-hexane. The templating mechanism of the designed mesoporogens as well as the effects of their phosphorus content on the properties of hierarchical SAPO-11 molecular sieves were well discussed. This work provides an effective approach to template intracrystal mesopores in hierarchical silicoaluminophosphate molecular sieves.