18868-43-4 Usage
Description
Molybdenum (IV) oxide, also known as molybdenum dioxide (MoO2), is a transition metal oxide that exhibits good electrical conductivity due to the presence of delocalized electrons in its valence band. It is typically prepared by reducing MoO3 in dry hydrogen within a temperature range of 450-550°C. Molybdenum (IV) oxide is characterized by its lead-gray color, nonvolatile nature, and semiconducting properties.
Uses
1. Used in Chemical Industry:
Molybdenum (IV) oxide is used as a catalyst for the dehydrogenation of alcohols, contributing to the production of various chemicals and intermediates.
2. Used in Electronics Industry:
Molybdenum (IV) oxide is utilized as an intermediate and processing aid in the electronics industry, taking advantage of its electrical conductivity and semiconducting properties.
3. Used in Manufacturing of Molybdenum Nano-wires:
Molybdenum (IV) oxide plays a crucial role in the production of molybdenum nano-wires, which have potential applications in various fields due to their unique properties.
4. Used in Energy Applications:
Molybdenum (IV) oxide is employed as an anode material in rechargeable lithium batteries and fuel-flexible solid oxide fuel cells, capitalizing on its electrical conductivity and energy storage capabilities.
5. Used in Hydrogen Reforming Processes:
Molybdenum (IV) oxide serves as a catalyst in hydrogen reforming processes, which are essential for producing hydrogen gas for various industrial applications.
Physical and Chemical Properties:
Molybdenum (IV) oxide can be prepared by several methods, including controlled oxidation of molybdenum and controlled reduction of MoO3 with hydrogen. The pure oxide suitable for structure determination has been prepared by electrolysis of a polymolybdate (K2O5.MoO3) solution. It is insoluble in water and inert in solutions of nonoxidizing acids or bases, but can be dissolved by oxidizing solutions. At high temperatures (~1100°C), it dissociates into Mo and MoO3. Crystalline MoO2 appears violet or brown and has a deformed rutile structure consisting of infinite chains of MoO6 octahedra. It is diamagnetic and semiconducting, with metal-metal bonds present. Some of its thermodynamic properties include G°f29% ~ 172.415 kcal/mole, H°f29% -140.5 kcal/mole, and S°298 11.954 gibbs/mole. It is also a nonvolatile powder with a density of approximately 6.4 and is insoluble in hydrochloric acid, hydrogen fluoride, and alkalies, while being sparingly soluble in sulfuric acid.
Preparation
Molybdenum(IV) oxide is obtained by passing steam over red hot molybdenum:
Mo + 2H2O → MoO2 + 2H2
Alternatively, the oxide may be prepared by heating a molybdate salt, such as ammonium molybdate, with a reducing agent such as zinc. The dioxide also may be obtained along with other oxides of molybdenum when molybdenum metal is heated in air.
A brown-black suspension of MoO2 in hydrate form may be obtained by reducing a solution of ammonium molybdate with hydrogen in the presence of colloidal palladium.
Hazard
Toxic material.
Safety Profile
Poison by
subcutaneous route. Incandescent reaction
with air. When heated to decomposition it
emits toxic fumes of Mo.
Check Digit Verification of cas no
The CAS Registry Mumber 18868-43-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,8,8,6 and 8 respectively; the second part has 2 digits, 4 and 3 respectively.
Calculate Digit Verification of CAS Registry Number 18868-43:
(7*1)+(6*8)+(5*8)+(4*6)+(3*8)+(2*4)+(1*3)=154
154 % 10 = 4
So 18868-43-4 is a valid CAS Registry Number.
InChI:InChI=1/Mo.2O/q+4;2*-2
