For many years, it has been customary to classify catalysts as homogeneous or heterogeneous. Generally, the former are more active and more selective. But the major disadvantage of the homogeneous catalysts is the need to separate the reaction products and to recover the catalyst, which is often somewhat more expensive than a classical heterogeneous catalyst. It has been considered, especially in the last ten years, that there might be advantages in chemically binding a homogeneous catalyst to a solid support.
Polymer-bound, anthranilic acid anchored rhodium (I) catalysts have been prepared. The rate of hydrogenation of cyclohexene has been studied quantitatively, and its dependence on factors such as substrate and catalyst concentration, temperature, and pressure has teen determined. A possible mechanism has been proposed. Hydrogen-deuterium exchange has also been studied