Introduction There is a demand for rational methods for the development of new catalysts. Strong efforts in this direction have led to a deeper insight into catalytic phenomena on a molecular level. A key design consideration in catalysis is the optimum pore structure of catalyst particles. Design parameters may be distribution of pore radii, distribution of pore length, pore shape, distribution of catalyst crystallites (active centers) within the pores or connectivity. The variable design parameters are constrained between upper and lower bounds due to physical limitations. We have taken hydrodemetallation of crude oil as an example for optimization of three-dimensional network models of catalyst supports. During the hydrodemetallation process metal-bearing molecules present in the feed diffuse into the catalyst pellet, react at the active sites on the surface of catalyst within the pores and deposit as coke and metal sulfides. This process leads to changes of the morphology