Molybdenum(IV) oxide

Molybdenum dioxide

Red - brown, odorless solid

Fixed

6.47 g · cm -3

1100 ° C ( decomposition)

Poorly in water ( 1.4 g · l-1 at 20 ° C)

Attention

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Molybdenum ( IV) oxide is a chemical compound selected from the group of the oxides.

Occurrence

Molybdenum (IV ) oxide is very rare naturally as the mineral Tugarinovit.

Production and representation

Molybdenum ( IV) oxide can be obtained by reduction of molybdenum ( VI) oxide with hydrogen, ammonia or elemental molybdenum at high temperatures:

Larger crystals can be obtained at 700 ° C by the chemical transport of polycrystalline molybdenum ( IV) oxide with iodine in a temperature gradient 900.

Properties

Molybdenum ( IV) oxide is a brown- violet solid which is sparingly soluble in water. It has a monoclinic crystal structure with space group P21 / c ( a = 558.4 pm, b = 484.2 pm, c = 560.8 pm, ß = 120.59 °). Very finely divided powder is self-igniting in air.

Use

Molybdenum ( IV) oxide may be used as a catalyst for the dehydrogenation of alcohols.