Platinum bronzes III. A reinvestigation of the composition of Adams' catalyst (1)

Abstract The platinum oxide, commonly known as Adams' catalyst and formulated as PtO2 · H2O, has been found to be a mixture of Pt, α-PtO2 (possibly hydrated) and NaxPt3O4, sodium platinum bronze. Both α-PtO2 and NaxPt3O4 are active as hydrogenating agents for cyclopentene and benzene, but α-PtO2 is converted completely to Pt metal, while only minor decomposition to the metal occurs for NaxPt3O4. It is suggested that the irreproducibility of the activity of Adams' oxide might be caused by a variation of the relative amounts of Pt metal and the oxides in the mixture. Methods for preparing a more consistent catalyst are discussed.