Protactinium(IV) oxide
IUPAC name
Protactinium(IV) oxide
  • 12036-03-2
3D model (JSmol)
  • InChI=1S/2O.Pa checkY
  • O=[Pa]=O
Molar mass 263.034 g·mol−1
Appearance Black crystals
NFPA 704 (fire diamond)
Special hazard RA: Radioactive. E.g. plutonium
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Protactinium(IV) oxide is a chemical compound with the formula PaO2. The black oxide is formed by reducing Pa2O5 with hydrogen at 1 550 °C. Protactinium(IV) oxide does not dissolve in H2SO4, HNO3, or HCl solutions, but reacts with HF.[1][2]: 195 

As protactinium(IV) oxide, like other protactinium compounds, is radioactive, toxic and very rare, it has no known technological use.


  1. ^ Sellers, Philip A.; Fried, Sherman; Elson, Robert E.; Zachariasen, W. H. (1954). "The Preparation of Some Protactinium Compounds and the Metal". Journal of the American Chemical Society. 76 (23): 5935. doi:10.1021/ja01652a011.
  2. ^ Boris F. Myasoedov, H. W. Kirby, & Ivan G. Tananaev (2006) Protactinium, Chapter 4 in Morss, Lester R. & Edelstein, Norman M. & Fuger, Jean, (edit.) The Chemistry of the Actinide and Transactinide Elements (PDF) (3. painos). Dordrecht: Springer. ss. 161–252.