Nomenclature
CAS number: 1314-15-4
Platinum dioxide; Adams' catalyst.
O
2Pt; mol wt 227.08.
O 14.09%, Pt 85.91%.
PtO
2.
Description and references
Prepd by the interaction of platinic chloride
and excess NaOH: W"ohler, Z. Anorg. Chem. 40, 434 (1904); Bellucci ibid. 44, 171 (1905); by the reduction of chloroplatinic acid
with formaldehyde: Willst"atter, Waldschmidt-Leitz, Ber. 54, 113 (1921); Feulgen, ibid. 360; by fusing chloroplatinic acid with sodium nitrate:
Adams et al., Org. Synth. 8, 92 (1928). Determination of orthorhombic (CaCl2) crystal structure of β-PtO2: Siegel et
al., J. Inorg. Nucl. Chem. 31, 3803 (1969).
Properties
Several hydrates have been reported; the compd
generally used for catalysis is the monohydrate. Black powder. When
freshly pptd it is sol in concd acids, also in dil H3PO4, esp when warmed. Easily sol in dilute solns of potassium
hydroxide.Use
As catalyst in hydrogenations. The actual catalyst
is platinum black which is formed
in situ by reduction
of the PtO
2 by the hydrogen used for the hydrogenation.
Especially useful for reduction at room temp and hydrogen pressures
up to 4 atmospheres. Suitable for the reduction of double and triple
bonds, aromatic nuclei, carbonyl groups, nitro groups, and nitriles.