COMPUTER-SIMULATION OF GAMMA-AL2O3 MICROCRYSTAL

A molecular dynamics simulation of a gamma-Al2O3 microcrystal has been performed in order to investigate the structure of both the surface a nd the bulk. Ou results show that an approximately cubic particle of 6 0 Angstrom per side has a crystalline inner structure and an amorphous phase which constitutes the proper surface with a depth of about 12 A ngstrom. Some structural properties of this important catalytic suppor t are analyzed and confirm both results from previous simulations on t he surface and the bulk and from experimental investigations by other authors. The nature of Lewis acid sites is also considered and compare d with recent studies based on Al-27 CP-MAS and IR spectroscopy.