Zirconium-SAPO-11 The peculiar effect of zirconium addition on the catalytic properties for n-buteneisomerization

SAPO-11 and Zr-SAPO-11 solids were synthesized by hydrothermal methods and characterized. Zirconium is not incorporated in the SAPO-11 framework but is localized, at least partially, in the pores of the solid, inducing a partial pore blockage. When used in n-butene isomerization, both solids are active and selective but Zr-SAPO-11 exhibited higher isobutene selectivity as compared to SAPO-11. This improved isobutene selectivity for Zr-SAPO-11 catalyst is attributed to the presence of zirconium in the pores causing an increased shape selectivity.