Plutonium hydride

{{Chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 405393807

| IUPACName = Plutonium dihydride (excess hydrogen)

| SystematicName = Plutonium(2+) hydride

| OtherNames = Plutonium dihydride

Plutonium(II) hydride

Plutonous hydride

|Section1={{Chembox Identifiers

| CASNo = 17336-52-6

| CASNo_Ref = {{cascite|correct|??}}

| ChemSpiderID = 57566567

| PubChem = 57464762

| SMILES = [H-].[H-].[Pu++]

| StdInChI = 1S/Pu.2H/q+2;2*-1

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = IPKHWWGTRXXYCX-UHFFFAOYSA-N

| StdInChIKey_Ref = {{stdinchicite|changed|??}}

}}

|Section2={{Chembox Properties

| H=2 | Pu=1

| Appearance = Black, opaque crystals

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Plutonium hydride is a non-stoichiometric chemical compound with the formula PuH{{sub|2+x}}. It is one of two characterized hydrides of plutonium; the other is PuH{{sub|3}}.Gerd Meyer, 1991, Synthesis of Lanthanide and Actinide Compounds Springer, {{ISBN|0-7923-1018-7}}. PuH{{sub|2+x}} is non-stoichiometric with a composition range of PuH{{sub|2}} – PuH{{sub|2.7}}. Metastable stoichiometries with an excess of hydrogen (PuH{{sub|2.7}} – PuH{{sub|3}}) can also be formed. PuH{{sub|2}} 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{{sub|2}} 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, {{ISBN|9789048131464}}

:Pu + H{{sub|2}} → PuH{{sub|2}}

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 Pu{{sub|2}}O{{sub|3}}, plutonium dioxide and a higher oxide identified by X-ray diffraction and X-ray photoelectron spectroscopy as the mixed-valence phase Pu{{sup|IV}}{{sub|3−x}}Pu{{sup|VI}}{{sub|x}}O{{sub|6+x}}.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, {{doi|10.1016/0925-8388(93)90547-Z}}. Investigation of the reaction performed without heating suggests that the reaction of Pu metal and moist air the production of PuO{{sub|2}} and a higher oxide along with adsorbed hydrogen, which catalytically combines with O{{sub|2}} 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{{sub|2}} and N{{sub|2}} 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, {{doi|10.1016/S0925-8388(01)00932-X}}.