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.