What is SAPO-11?

SAPO-11 is an AEL-type silicoaluminophosphate molecular sieve with one-dimensional 10-membered ring elliptical channels (~4.0 × 6.5 Å). Unlike the cage-based CHA frameworks (SAPO-34, SSZ-13) or large-pore 12-MR zeolites (Beta, Y), SAPO-11’s 1D channel system provides a constrained environment that favours isomerization over cracking — the property that makes it the reference catalyst for hydroisomerization of long-chain n-alkanes.

SAPO-11’s mild acidity comes from silicon substitution into the neutral AlPO₄ framework, with Si content typically 3-10 mol%. This mild acidity, combined with the shape constraints of the 10-MR elliptical pores, allows SAPO-11 to selectively isomerize n-paraffins to branched iso-paraffins while suppressing the secondary cracking that would reduce liquid yield. When formulated with a noble metal (Pt or Pd), Pt/SAPO-11 is the standard bifunctional catalyst for catalytic dewaxing — improving cold-flow properties of lubricant base oils and diesel without sacrificing yield to cracking.

For detailed specifications and grade selection, see the SAPO-11 product hub.