Synthesis of Zn-containing microporous aluminophosphate with the STA-1 structure

Abstract

Zn atoms have been incorporated into the STA-1 microporous framework (SAO framework type) for the first time. Pure Zn-containing STA-1 aluminophosphate has been obtained in the presence of either (S)-(−)-N-benzylpyrrolidine-2-methanol (BPM) or benzylpyrrolidine (BP) as structure-directing agent. Characterisation results have demonstrated that the organic molecules remain intact within the microporous framework after the hydrothermal treatment. The X-ray diffraction pattern has been indexed in the tetragonal space group Im2 (a = 13.7828(1) Å and c = 21.9444(4) Å). Chemical analysis and ³¹P MAS NMR spectroscopy confirm the incorporation of ca. 4.5 Zn atoms per unit cell by isomorphous substitution of Al. This large-pore aluminophosphate has one of the lowest framework densities among the known zeolite structures, and is therefore of potential interest for applications in adsorption or catalytic processes involving bulky molecules.