Cerium(III) oxide

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Cerium(III) oxide
Cerium(III) oxide
Names
IUPAC name
Cerium(III) oxide
Other names
Cerium sesquioxide
Identifiers
1345-13-7 YesY
Properties
Ce2O3
Molar mass 328.24 g/mol
Appearance yellow/green pulver,
Density 6.2 g/cm3
Melting point 2,177 °C (3,951 °F; 2,450 K)
Boiling point 3,730 °C (6,750 °F; 4,000 K)
insoluble
Solubility in sulfuric acid soluble
Solubility in hydrochloric acid insoluble
Structure
Hexagonal, hP5
P-3m1, No. 164
Vapor pressure {{{value}}}
Related compounds
Other anions
Cerium(III) chloride
Other cations
Lanthanum oxide, Praseodymium(III) oxide
Related compounds
CeO2
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY verify (what is YesYN ?)
Infobox references

Cerium(III) oxide is an oxide of the rare earth metal cerium. It has chemical formula Ce2O3, and is gold-yellow in color.

Applications

Engine and exhaust catalysts

Cerium oxide is used as a catalytic converter for the minimisation of CO emissions in the exhaust gases from motor vehicles.

When there is a shortage of oxygen, cerium(IV) oxide is reduced by carbon monoxide to cerium(III) oxide:

2 CeO
2
+ CO → Ce
2
O
3
+ CO
2

When there is an oxygen surplus, the process is reversed and cerium(III) oxide is oxidized to cerium(IV) oxide:

2 Ce
2
O
3
+ O
2
→ 4 CeO
2

Major automotive applications for cerium(III) oxide are, as a catalytic converter for the oxidation of CO and NOx emissions in the exhaust gases from motor vehicles,[1][2] and secondly, cerium oxide finds use as a fuel additive to diesel fuels, which results in increased fuel efficiency and decreased hydrocarbon derived particulate matter emissions,[3] however the health effects of the cerium oxide bearing engine exhaust is a point of study and dispute.[4][5][6]

Water splitting

The cerium(IV) oxide–cerium(III) oxide cycle or CeO2/Ce2O3 cycle is a two step thermochemical water splitting process based on cerium(IV) oxide and cerium(III) oxide for hydrogen production.[7]

Illumination

Cerium(III) oxide combined with tin(II) oxide (SnO) in ceramic form is used for illumination with UV light. It absorbs light with a wavelength of 320 nm and emits light with a wavelength of 412 nm.[8] This combination of cerium(III) oxide and tin(II) oxide is rare, and obtained only with difficulty on a laboratory scale.

Production

Cerium(III) oxide is produced by the reduction of cerium(IV) oxide with hydrogen at approximately 1,400 °C (2,550 °F) to make air stable cerium(III) oxide.

References

External links