Cerium(III) oxide

Cerium(III) oxide
Cerium(III) oxide
IUPAC name
Cerium(III) oxide
Other names
Cerium sesquioxide
Identifiers
CAS number 1345-13-7 YesY
Properties
Molecular formula Ce2O3
Molar mass 328.24 g/mol
Appearance yellow/green pulver,
Density 6.2 g/cm3
Melting point

2177 °C
Solubility in water insoluble
Solubility in sulfuric acid soluble
Solubility in hydrochloric acid insoluble
Structure
Crystal structure Hexagonal, hP5
Space group P-3m1, No. 164
Related compounds
Related compounds CeO2
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.

Contents

Applications

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 CeO2 + CO → Ce2O3 + CO2

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

2 Ce2O3 + O2 → 4 CeO2

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.[1]

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.[2] 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. Production at other temperatures results in pyrophoric cerium(III) oxide.[3]

References

  1. ^ Hydrogen production from solar thermochemical water splitting cycles
  2. ^ Spectral Studies of New Luminophors for Dental Porcelain
  3. ^ Georg Brauer: Handbuch der Präparativen Anorganischen Chemie Band II, Seite 1090, Ferdinand Enke Verlag Stuttgart 1978, ISBN 3-432-87813-3

External links