Adams Catalyst

A dark brown powder, a hydrated form of platinum (IV) oxide (PtO2), produced by heating chloroplatinic acid (H2PtC16) with sodium nitrate (NaNO3). Platinum ni­trate is produced, and this decom­poses to Platinum (IV) oxide with evolution of NO2 and oxygen. It is used in hydrogenations of alkenes to alkanes, nitro compounds to aminos, and ketones to alcohols. The actual catalyst is not the oxide but finely di­vided platinum black, which forms during the hydrogenation reaction.