Plutonium dihydride is a non-stoichiometric chemical compound with the formula PuH. It is one of two characterized hydrides of plutonium; the other is PuH.Gerd Meyer, 1991, Synthesis of Lanthanide and Actinide Compounds Springer, . PuH has a composition range of PuH – PuH. Metastable stoichiometries with an excess of hydrogen (PuH – PuH) can also be formed. PuH has a cubic structure. It is readily formed from the elements at 1 atmosphere at 100–200°C: When the stoichiometry is close to PuH it has a silver appearance, but gets blacker as the hydrogen content increases, additionally the color change is associated with a reduction in conductivity.The Chemistry of the Actinide and Transactinide Elements, Lester R. Morss, Norman M. Edelstein, J. Fuger, Springer, 2010,
Pu + H → PuH
Studies of the reaction of plutonium metal with moist air at 200–350 °C showed the presence of cubic plutonium hydride on the surface along with PuO, PuO and a higher oxide identified by X-ray diffraction and X-ray photoelectron spectroscopy as the mixed-valence phase PuPuO.J. L. Stakebake, D. T. Larson, J. M. Haschke: Characterization of the Plutonium-water Reaction II: Formation of a Binary Oxide containing Pu(VI), Journal of Alloys and Compounds, 202, 1–2, 1993, 251–263, . Investigation of the reaction performed without heating suggests that the reaction of Pu metal and moist air the production of PuO and a higher oxide along with adsorbed hydrogen, which catalytically combines with O to form water.J. M. Haschke, T. H. Allen, L. A. Morales: Surface and Corrosion Chemistry of Plutonium, Los Alamos Science, 2000, 252.
Like the free metal, plutonium dihydride is pyrophoric. On the surface of hydrided plutonium, it acts as a catalyst for the oxidation of the metal with consumption of both O and N from air.John M. Haschke Thomas H. Allen: Plutonium Hydride, Sesquioxide and Monoxide Monohydride: Pyrophoricity and Catalysis of Plutonium Corrosion, Journal of Alloys and Compounds, 320, 1, 2001, 58–71, .
See also Uranium hydride bomb
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