Palladium on carbon (Pd/C) is a common catalyst for hydrogenation and/or hydrogenolysis of various functional groups. It is typically purchased as a black powder which is 5% or 10% palladium (by wt%) adsorbed on carbon. The reagent is normally purchased dry or as a solid which is 50% wet with water. The 50% wet with water reagent is the safer to handle option.

Palladium-catalyzed hydrogenolysis is often the final step in challenging natural product total syntheses and a key step in industrial processes producing fine chemicals. Here, we demonstrate that there is wide variability in the efficiency of commercial sources of palladium on carbon (Pd/C) resulting in significant differences in selectivity, reaction times, and yields. We identified the physicochemical properties of efficient catalysts for hydrogenolysis: (1) small Pd/PdO particle size (2) homogeneous distribution of Pd/PdO on the carbon support, and (3) palladium oxidation state are good predictors of catalytic efficiency. Now chemists can identify and predict a catalyst's efficiency prior to the use of valuable synthetic material and time.
