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