Complete reduction to the alkane occurs when palladium on carbon (Pd/C) is used as catalyst, but hydrogenation can be stopped at the alkene if the less active lindlar catalyst is used . the lindlar catalyst is a finely divided palladium metal thet has been precipitated onto a calcium cartate and quinoline ,an aromatic amine. The hydrogenation occurs with syn stereochemistry (section 7.5), giving a cis alkene product.