| 词条 | Molybdenum trioxide |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 431943482 | ImageFileL1 = Molybdän(VI)-oxid Kristallstruktur.png | ImageName = Molybdenum trioxide | ImageFileR1 = Molybdenum trioxide powder.jpg | ImageName1 = Molybdenum trioxide | IUPACName = Molybdenum trioxide | OtherNames = Molybdic anhydride Molybdite Molybdic trioxide |Section1={{Chembox Identifiers | CASNo = 1313-27-5 | CASNo_Ref = {{cascite|correct|CAS}} | PubChem = 14802 |Section2={{Chembox Properties | Mo=1 | O=3 | Appearance = yellow or light blue solid | Odor = odorless | Density = 4.69 g/cm3, solid | Solubility = 0.1066 g/100 mL (18 °C) 0.490 g/100 mL (28 °C) 2.055 g/100 mL (70 °C) | MeltingPtC = 795 | BoilingPtC = 1155 | BoilingPt_notes = sublimes | pKa = | MagSus = +3.0·10−6 cm3/mol |Section3={{Chembox Structure | Coordination = see text | CrystalStruct = orthorhombic |Section4={{Chembox Thermochemistry | DeltaHf = −745.17 kJ/mol | Entropy = 77.78 J K−1 mol−1 |Section7={{Chembox Hazards | ExternalSDS = | EUClass = Carc. Cat. 3 Harmful (Xn) Irritant (Xi) | RPhrases = {{R36/37}}, {{R40}} | SPhrases = {{S2}}, {{S22}}, {{S36/37}} | NFPA-H = 3 | NFPA-F = 0 | NFPA-R = | NFPA-S = OX | FlashPt = Non-flammable | LD50 = 125 mg.kg (rat, oral){{citation needed|date=July 2015}} 2689 mg/kg (rat, oral)[1] | LC50 = >5840 mg/m3 (rat, 4 hr)[1] | LDLo = 120 mg Mo/kg (rat, oral) 120 mg Mo/kg (guinea pig, oral)[1] |Section8={{Chembox Related | OtherAnions = | OtherCations = Chromium trioxide Tungsten trioxide | OtherFunction = Molybdenum dioxide "Molybdenum blue" | OtherFunction_label = molybdenum oxides | OtherCompounds = Molybdic acid Sodium molybdate }}Molybdenum trioxide is chemical compound with the formula MoO3. This compound is produced on the largest scale of any molybdenum compound. It occurs as the rare mineral molybdite. Its chief application is as an oxidation catalyst and as a raw material for the production of molybdenum metal.[2] StructureIn the gas phase, three oxygen atoms are double bonded to the central molybdenum atom. In the solid state, anhydrous MoO3 is composed of layers of distorted MoO6 octahedra in an orthorhombic crystal. The octahedra share edges and form chains which are cross-linked by oxygen atoms to form layers. The octahedra have one short molybdenum-oxygen bond to a non-bridging oxygen.[3][4] {{clear|left}}Preparation and principal reactionsMoO3 is produced industrially by roasting molybdenum disulfide, the chief ore of molybdenum:[2] 2 MoS2 + 7 O2 → 2 MoO3 + 4 SO2 The laboratory synthesis of the dihydrate entails acidification of aqueous solutions of sodium molybdate with perchloric acid:[5] Na2MoO4 + H2O + 2 HClO4 → MoO3(H2O)2 + 2 NaClO4 The dihydrate loses water readily to give the monohydrate. Both are bright yellow in color. Molybdenum trioxide dissolves slightly in water to give "molybdic acid". In base, it dissolves to afford the molybdate anion. UsesMolybdenum trioxide is used to manufacture molybdenum metal, which serves as an additive to steel and corrosion-resistant alloys. The relevant conversion entails treatment of MoO3 with hydrogen at elevated temperatures: MoO3 + 3 H2 → Mo + 3 H2O It is also a component of the co-catalyst used in the industrial production of acrylonitrile by the oxidation of propene and ammonia. Because of its layered structure and the ease of the Mo(VI)/Mo(V) coupling, MoO3 is of interest in electrochemical devices and displays.[6] Molybdenum trioxide has also been suggested as a potential anti-microbial agent, e.g., in polymers. In contact with water, it forms H+ ions that can kill bacteria effectively.[7] However, the issue of keeping the catalyst clean in an environment that would exploit such antimicrobial properties has not been explored. References1. ^1 2 {{IDLH|moly-mo|Molybdenum (soluble compounds, as Mo)}} 2. ^1 {{cite encyclopedia|authors=Roger F. Sebenik|display-authors=etal|title=Molybdenum and Molybdenum Compounds|encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|year=2005|publisher=Wiley-VCH|location=Weinheim|doi=10.1002/14356007.a16_655}} 3. ^1 Molybdite Mineral Data 4. ^Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. {{ISBN|0-19-855370-6}}. 5. ^{{cite journal|doi=10.1002/9780470132555.ch56|author1=Heynes, J. B. B. |author2=Cruywagen, J. J. |title=Yellow Molybdenum(VI) Oxide Dihydrate |journal=Inorganic Syntheses|year= 1986| volume =24|pages=191-2}} 6. ^{{cite journal|author1=Ferreira, F. F. |author2=Souza Cruz, T. G. |author3=Fantini, M. C. A. |author4=Tabacniks, M. H. |author5=de Castro, S. C. |author6=Morais, J. |author7=de Siervo, A. |author8=Landers, R. |author9=Gorenstein, A. |doi=10.1016/S0167-2738(00)00483-5|title=Lithium insertion and electrochromism in polycrystalline molybdenum oxide films|year=2000|journal=Solid State Ionics|volume=136–137|pages=357}} 7. ^{{cite journal|doi=10.1016/j.msec.2011.09.010|title=Antimicrobial activity of transition metal acid MoO3 prevents microbial growth on material surfaces|year=2012|last1=Zollfrank|first1=Cordt|last2=Gutbrod|first2=Kai|last3=Wechsler|first3=Peter|last4=Guggenbichler|first4=Josef Peter|journal=Materials Science and Engineering: C|volume=32|pages=47}} External links
2 : Molybdenum(VI) compounds|Oxides |
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