Computational study of the structural and electronic properties of dopant ions in microporous A1POs. 1. Acid catalytic activity of divalent metal ions

Periodic ab initio QM calculations are applied to study the structure and acidity of Mg, Ca, Cr, Mn, Fe, Co, Ni, Zn, and Sr divalent metal ions in the A1PO-34 framework, charge compensated by an acid proton on a neighboring oxygen. The results show that the local environment of the divalent dopants is a distorted tetrahedron, in which the Me-O(sub H) bond of the dopant to the protonated oxygen is ~0.15 degree angstron longer than the other three Me-O bonds.