PURPOSE: To recover a particularly costly metal-contg. catalyst in active form allowing immediate re-use by first removing the solvent of a catalyst reaction mixture, then adding a lower alkanoic acid to the catalyst to allow precipitation of a homogeneous catalyst and recovering the catalyst.

CONSTITUTION: At the time of recovering the homogeneous catalyst, the reaction solvent is first removed by a method, such as distillation. The lower alkanoic acid, such as formic acid or propionic acid, is then added to the catalyst. The homogeneous catalyst, then, precipitates and, therefore, the catalyst is recovered by a method, such as centrifugation or filtration. If the catalyst is recovered in such a manner, the catalyst contg. the costly metal, such as platinum group metal salt of carboxylic acid, may be recovered. Even more the recovered catalyst is active and is reusable without processing.