Synthesis, thermal stability, and structure of (V[sub. 13]Mo[sub. 87])O[sub 2. 935]: A new oxide with the open [open quotes]Hexagonal MoO[sub 3][close quotes] structure

Journal Article · Sun Aug 01 04:00:00 EDT 1993 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1006/jssc.1993.1241· OSTI ID:7284154

Hu, Y; Davies, P K ^[1]

---

1. Univ. of Pennsylvania, Philadelphia, PA (United States)

New oxides with the stoichiometry (Li[sub x]H[sub .13[minus]x])(V[sub .13]Mo[sub .87])O[sub 3][center dot]0.26H[sub 2]O and the structure of [open quotes]hexagonal MoO[sub 3][close quotes] have been precipitated directly from Li-V-Mo aqueous solutions. At room temperature in dilute HCl, these precipitates undergo a rapid ion-exchange reaction to give the pure protonic form of vanadium-stabilized hexagonal MoO[sub 3], H[sub .13](V[sub .13]Mo[sub .87])O[sub 3][center dot]0.26H[sub 2]O. Complete dehydration of this solid acid yields a new oxide (V[sub .13]Mo[sub .87])O[sub 2.935] which retains the structure of hexagonal MoO[sub 3] up to 460[degrees]C. Whereas all the previously reported compounds with the hexagonal MoO[sub 3] framework have contained large stabilizing cations in the one dimensional channels of the structure, (V[sub .13]Mo[sub .87])O[sub 2.935] represents the open form of hexagonal MoO[sub 3] and has empty channels with free diameters approaching 3.3 [angstrom]. Powder neutron diffraction was used to confirm the structure of (V[sub .13]Mo[sub .87])O[sub 2.935] which was refined in space group P6[sub 3] with final lattice parameters of a = 10.593(1), c = 3.6944(4) [angstrom]; V = 359.01 [angstrom][sup 3]. The [open quotes]porosity[close quotes] of this structure is significantly, [approx] 12-18%, greater than the [alpha], [beta], and [beta][prime] polymorphs of MoO[sub 3].

• OSTI ID: 7284154
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 105:2; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CHALCOGENIDES
CHEMICAL PREPARATION
CRYSTAL STRUCTURE
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
STOICHIOMETRY
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES