THE SUPERACIDITY OF SULFATED ZIRCONIA - AN AB-INITIO QUANTUM-MECHANICAL STUDY

It has been experimentally shown that the surface of sulfated zirconia exhibits superacidic behavior. To understand the properties of this surface, several molecular models involving one zirconium atom have been considered. Ab-initio Hartree-Fock calculations have been performed on these systems. Their structures have been determined and compared. Their Lewis and Bronsted acidities have been evaluated with reference to weak bases: carbon monoxide for the Lewis acidity and water for the Bronsted one. The computations show that the superacidity is of the Bronsted type. They emphasize the role played by the residual water in the experiments.