Supported Ni, Co, Pt and Ir catalysts were studied by temperature programmed gas phase hydrogenation (TPH) of toluene to evaluate the performance of the catalysts and to obtain information about the applicability of temperature programming to hydrogenation studies. On all catalysts the reaction rate passed through a maximum as the temperature increased. The maximum reaction rate was reached at slightly lower temperatures with the Co catalyst than the Ni, Pt and Ir catalysts. This work demonstrates that TPH is a rapid method for evaluating the performance of hydrogenation catalysts and, combined with temperature programmed desorption, provides information on the reaction mechanism unobtainable from isothermal experiments.