≥98%
Synonym: Divanadium pentaoxide,
Divanadium pentoxide, Pentaoxodivanadium, Vandia
·
Linear Formula V2O5
·
Molecular Weight 181.88
Properties
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Related Categories
|
Catalysis
and Inorganic Chemistry, Chemical
Synthesis,Materials
Science, Materials
for Buffer Layer, Metal
and Ceramic Science,
More...
|
|
InChI Key
|
GNTDGMZSJNCJKK-UHFFFAOYSA-N
|
|
assay
|
≥98%
|
|
mp
|
690 °C(lit.)
|
|
density
|
3.35 g/mL at
25 °C(lit.)
|
Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a
brown/yellow solid, although when freshly precipitated from aqueous solution,
its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the
industrial perspective, it is the most important compound of vanadium, being
principal precursor to alloys of vanadium and is a widely used industrial
catalyst.
Detailed description
The
mineral form of this compound, shcherbinaite, is extremely rare, almost always
found among fumaroles. A mineral trihydrate, V2O5·3H2O,
is also known under the name of navajoite.
Preparation
Technical grade V2O5 is produced as a black powder used for
the production of vanadium metal and ferrovanadium.[6] A vanadium ore or
vanadium-rich residue is treated with sodium carbonate to produce sodium metavanadate, NaVO3. This material is then acidified to
pH 2–3 using H2SO4 to yield a
precipitate of "red cake" (see above). The red cake is then melted at 690 °C to
produce the crude V2O5.
Vanadium(V) oxide is produced when vanadium metal is heated with
excess oxygen, but this product is contaminated with other, lower
oxides. A more satisfactory laboratory preparation involves the decomposition
of ammonium metavanadate at around
200 °C:
2
NH4VO3 → V2O5 + 2 NH3 + H2O
Uses
Ferrovanadium production
In terms of quantity, the dominant use for
vanadium(V) oxide is in the production of ferrovanadium (see above). The oxide is heated with scrap iron and ferrosilicon, with lime added to form a calcium silicateslag. Aluminium may
also be used, producing the iron-vanadium alloy along with alumina as a by-product.[6]
Sulfuric acid production
Another important use of vanadium(V) oxide is in the
manufacture of sulfuric acid, an important
industrial chemical with an annual worldwide production of 165 million metric
tons in 2001, with an approximate value of US$8 billion. Vanadium(V) oxide
serves the crucial purpose of catalysing the
mildly exothermic oxidation of sulphur dioxide
to sulphur trioxide by air in the contact process:
2
SO2 + O2 ⇌
2 SO3
The discovery of this simple reaction, for which V2O5 is the most effective catalyst,
allowed sulfuric acid to become the cheap commodity chemical it is today. The
reaction is performed between 400 and 620 °C; below 400 °C the V2O5 is inactive as a catalyst, and above
620 °C it begins to break down. Since it is known that V2O5 can be reduced to VO2 by SO2, one likely
catalytic cycle is as follows:
SO2 + V2O5 → SO3 + 2VO2
followed by
2VO2 +½O2 → V2O5
It is also used as catalyst in the selective catalytic
reduction (SCR) of NOx emissions in some power plants. Due to its
effectiveness in converting sulfur dioxide into sulfur trioxide, and thereby
sulfuric acid, special care must be taken with the operating temperatures and
placement of a power plant's SCR unit when firing sulfur-containing fuels.
Other oxidations
C4H10 + 4 O2 → C2H2(CO)2O
+ 8 H2O
Phthalic anhydride is produced
similarly by V2O5-catalysed oxidation of ortho-xylene or naphthalene at 350–400 °C.
The equation is for the xylene oxidation:
C6H4(CH3)2 + 3 O2 → C6H4(CO)2O
+ 3 H2O
Phthalic anhydride is a precursor to plasticisers, used for conferring pliability
to polymers.
A variety of other industrial compounds are produced
similarly, including adipic acid, acrylic acid, oxalic acid, and anthraquinone.[5]
Other applications
Due to its high coefficient of thermal resistance,
vanadium(V) oxide finds use as a detector material in bolometers and microbolometer arrays for thermal imaging. It also finds
application as an ethanol sensor in ppm levels (up to 0.1 ppm).
Vanadium redox batteries are a type of flow battery used for energy
storage, including large power facilities such as wind farms.
Packaging
100, 500 g in glass
bottle
PRICE
$511.66/KG OR $232.57/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
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