P 1200a (OTTO) Palladium on calcium carbonate, 5% Pd) Cas 7440-05-3 - used for hydrogenolysis of cyclopropanes, benzyl derivatives, epoxides, hydrazines, and halides; P 1200a (OTTO) Palladium on calcium carbonate, 5% Pd Cas 7440-05-3 - used to dehydrogenate aromatics and deformylate aldehydes.