Preparation of catalysts of predetermined pore size distribution and pore volume

A process for the formation of a catalyst of predetermined pore size distribution and pore volume from an alumina hydrogel formed and obtained by precipitation from a solution containing a hydrous form of alumina in 1-5 wt. % concentration and an anion that is soluble in an alkaline solution and forms an aluminum salt, at pH 8-12, and temperature ranging about 15 DEG F.-120 DEG F., and then extended by contact with a water-soluble polymer containing from 2 to about 24 monomer units from the group consisting of (a) polyethylene glycols, (b) polypropylene glycols, and (c) polyethylene amines sufficient to absorb the polymer and displace water from the pores until the weight ratio of polymer:alumina ranges about 0.5:1 to about 4:1. The so formed alumina hydrogel in a series of steps, inclusive of the polymer extending step, is blended with make-up and recycle polymer for displacement of water and incorporation of the polymer, spray dried to convert the hydrogel to essentially boehmite powder of microspherical form, the boehmite powder mulled with water to form a paste, and the paste extruded to form extrudates. If desired, the extrudates are marumerized to form spheres. The extrudates or spheres, as desired, are extracted with a solvent to remove the polymer, and the alumina is then dried and calcined to form gamma alumina. In formation of the catalyst, a metal hydrogenation component, or components, is added during the initial alumina hydrogel forming step, added to the hydrogel after its precipitation from solution, or added to the gamma alumina after calcination.