A mesostructured gamma-alumina with a lathlike framework morphology, denoted MSU-gamma, has been prepared according to previously described methods through the reassembly and crystallization of a mesostructured alumina precursor with initially amorphous framework walls and used as a support for the catalytic hydrodesulfurization (HDS) of dibenzothiophene (DBT). The alumina support was loaded with molybdenum and cobalt ions via incipient wetness impregnation methods and then converted to the active sulfide form by reaction with H2S. HDS reactions of DBT were carried out at 400degreesC and 400 psi to achieve a DBT conversion of 69-77% and a biphenyl (BP) product selectivity of 60-64% after a reaction time of 3 h, indicating that most of the DBT could undergo desulfurization while limiting excessive hydrogen consumption through aromatic hydrogenation. Although the dispersion of the active Mo/Co sulfide phase supported on lathlike MSU-gamma alumina remained very high after several hours on stream, the conversions most likely were limited by a loss of surface area and porosity under HDS conditions. (C) 2003 Elsevier B.V. All rights reserved.