SAPO-11 Catalyst

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

The primary commercial application of SAPO-11 is in dewaxing and lube-oil hydroisomerization, where it selectively converts n-paraffins to branched iso-paraffins with minimal cracking. This improves cold-flow properties (pour point, cloud point) while preserving liquid yield — a significant advantage over traditional dewaxing catalysts that crack n-paraffins to lighter products.

SAPO-11 is a niche product with lower search volume than ZSM-5, Beta, or USY, but it fills a specific isomerization role that few other frameworks can match.

How to Select the Right SAPO-11 Grade

Silicon content controls acidity in SAPO-11. As a silicoaluminophosphate, acid sites arise from Si substitution into the neutral AlPO₄ framework. Si content of 3-10 mol% provides mild to moderate acidity; higher Si increases acid site density which can improve conversion but may also promote unwanted cracking.

Crystal size affects diffusion in the 1D channels. Smaller crystals reduce diffusion path length and improve access to acid sites, which is particularly important for long-chain n-alkanes (C₁₀-C₃₀+). Micron-grade powders are typical for catalyst formulation.

Binder and metal loading are usually handled by the catalyst formulator rather than the zeolite supplier. SAPO-11 is typically supplied as powder for incorporation into Pt/SAPO-11 or Pd/SAPO-11 bifunctional catalysts, where the noble metal provides hydrogenation-dehydrogenation and the SAPO-11 provides acid isomerization.

Available SAPO-11 Grades

Custom Si content, crystal size, and binder-ready formulations available on request.

Key Specifications

Isomerization and Dewaxing

SAPO-11 is the reference catalyst for hydroisomerization of n-alkanes in the C₁₀-C₃₀+ range. When formulated with a noble metal (typically 0.3-1.0 wt% Pt), Pt/SAPO-11 converts n-paraffins to mono-branched and di-branched iso-paraffins with high selectivity and low cracking. This is the basis for catalytic dewaxing processes that produce high-viscosity-index lubricant base oils with excellent cold-flow properties.

Compared to medium-pore zeolites like ZSM-5, SAPO-11’s milder acidity and elliptical 10-MR pores suppress cracking of branched products, preserving liquid yield. This is the key commercial advantage: better cold-flow without sacrificing yield.

Technical Documents

When requesting a sample, specify your target silicon content, crystal size, binder requirement, and whether you need SAPO-11 powder for Pt loading and formulation or a pre-formulated catalyst.