Incorporation of Mn, Co and Zn cations into large-pore aluminophosphate molecular sieves MeAPO-50.

Large-pore metal modified aluminophosphate molecular sieves MeAPO-50 (Me=Co,Zn,Mn) were synthesised by hydrothermal crystallisation using di-n-propylamine as structure directing agent. EXAFS and XRD analysis show that cobalt(II), manganese(II) and zinc(II) are incorporated into the non-phosphorus tetrahedral framework sites of MeAPO-50 on the threefold-axis site, and on a site in a general position in the unit cell. Results of both methods on distribution of the metal over the two sites are compared.