PR: It also forms during the hydrogen reduction of WO3 to W and can be obtained in pure state, for example, in hydrogen atmosphere at 900℃ and a water vapor partial pressure of 0.8 bar.
PP: D: 7.724-7.989 g•cm-3 (measured), 7.78 g•cm-3 (X-ray); CO: reddish violet, in whiskers brownish red; electrical resistivity: (2-3) x 10-4 Ω•cm; -ΔH°298 =743-780 kJ•mol-1; CR: monoclinic, P2/m-C12h; a=18.28 A, b= 3.775 A, c = 13.98 A, p = 115.14°.
The crystals are needle-shaped and the monoclinic b-axis is parallel to the needle axis; HR: WO2.7190-2.7224 at 1000℃.
WO2.72 is not included in the homologous series of CS structures, because besides edge- and corner-sharing octahedral also pentagonal columns exist (as described under tungsten bronzes).
CP:About behavior with respect to hydrogen. At elevated temperature it decomposes. It is soluble in alkaline solutions. Propene oxygen mixtures are oxidized by WO2.72 to acroleine.
A: It is partially contained in the technical blue oxide.
Inorder to get more information, you may visit our website: www.tungsten-powder.com
没有评论:
发表评论