The optimal control of a multi-bed catalytic reactor hosting an exothermic, reversible reaction is reconsidered. Several control problems, which differ by performance index significance and control configuration, have been solved. The performance index is either the total reactor production or an approximate expression of its operation benefit over a fixed time. Both practiced interstage cooling techniques, the indirect cooling (using interstage heat exchangers) and the direct cooling by injection of cold reactant (cold-shot), are analyzed. It is underlined that the cold-shot cooling is less performant due to the lower flexibility in the variation of feed temperatures on the beds and smaller Value of the reaction time.