Ceric Oxide

Ceric Oxide (CeO2) also known as cerium oxide, cerium dioxide is cleaning and polishing of silicon wafers, which are required by the electronic industry for ultra modern chip systems and solar cells. Its melting point is 2600 degree C, boiling point is 3500 degree C and specific gravity is 7.13. It is insoluble in water and is stable under ordinary conditions.

Send Requirement :


Request a Quote  **Free

No registration, no credit cards required.


Top Brands and Manufacturers

Show All Hide

Manufacturer and Suppliers for Ceric Oxide


Detailed Description for Ceric Oxide

Cerium(IV) oxide, also known as ceric oxide, ceria, cerium oxide or cerium dioxide, is an oxide of the rare earth metal cerium. It is a pale yellow-white powder with the chemical formula CeO2.Cerium(IV) oxide is formed by the calcination of cerium oxalate or cerium hydroxide.Powdered ceria is slightly hygroscopic and will also absorb a small amount of carbon dioxide from the atmosphere.[2]Cerium also forms cerium(III) oxide, Ce2O3, which is an unstable compound that will oxidize to cerium (IV) oxide under standard conditions for temperature and pressure.

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE white to pale-yellow powder

MELTING POINT

2600 C

BOILING POINT 3500 C
SPECIFIC GRAVITY 7.13

SOLUBILITY IN WATER

Insoluble
SOLVENT SOLUBILITY Soluble in sulfuric acid and nitric acid
PH

 

HARDNESS

6 (Mohs)

AUTOIGNITION

 

REFRACTIVE INDEX

 

NFPA RATINGS Health: 1; Flammability: 0; Reactivity: 0
FLASH POINT

 

STABILITY Stable under ordinary conditions, slightly hygroscopic

 

Purity CeO2-3.5N-1
TREO(WT%) 99.95
Al2O3/TREO 0.02%
CeO2/TREO 99.53%
SiO2/TREO 0.04%
MgO/TREO 0.00087%
K2O/TREO 0.01%
Na2O/TREO 0.10%
Fe2O3 0.011%
CaO 0.030%
TiO2 0.05%
L.O.L 0.37%
temperature 25C
humidity 70C

 

CeO2 is cleaning and polishing of silicon wafers, which are required by the electronical industry for ultra modern chip systems and solar cells. Due to the reaction of CeO2 with the processed material, it can be removed in a way extremely fine dosed which enables the manufacturing of ultra smooth surfaces, which pose the basic prerequisite for miniaturizing circuits. Together with aluminium oxide, cerium dioxide constitutes the material of first choice in the matter of chemical-mechanical polishing. Nano-structured cerium dioxide, among other things, is used as an oxygen-storing diesel additive in vehicle exhaust catalysts. 

 

Application:

Ceria has been used in catalytic converters in automotive applications. Since ceria can become non-stoichiometric in oxygen content (i.e. it can give up oxygen without decomposing) depending on its ambient partial pressure of oxygen, it can release or take in oxygen in the exhaust stream of a combustion engine. In association with other catalysts, ceria can effectively reduce NOx emissions as well as convert harmful carbon monoxide to the less harmful carbon dioxide. Ceria is particularly interesting for catalytic conversion economically because it has been shown that adding comparatively inexpensive ceria can allow for substantial reductions in the amount of platinum needed for complete oxidation of NOx and other harmful products of incomplete combustion.

Due to its fluorite structure, the oxygen atoms in a ceria crystal are all in a plane with one another, allowing for rapid diffusion as a function of the number of oxygen vacancies. As the number of vacancies increases, the ease at which oxygen can move around in the crystal increases, allowing the ceria to reduce and oxidize molecules or co-catalysts on its surface. It has been shown that the catalytic activity of ceria is directly related to the number of oxygen vacancies in the crystal, frequently measured by using X-ray photoelectron spectroscopy to compare the ratios of Ce3+ to Ce4+ in the crystal.

Ceria can also be used as a co-catalyst in a number of reactions, including the water-gas shift reaction[14] and steam reforming of ethanol or diesel fuel into hydrogen gas and carbon dioxide (with varying combinations of rhodium oxide, iron oxide, cobalt oxide, nickel oxide, platinum, and gold), the Fischer-Tropsch reaction, and selected oxidation (particularly with lanthanum). In each case, it has been shown that increasing the ceria oxygen defect concentration will result in increased catalytic activity, making it very interesting as a nanocrystalline co-catalyst due to the heightened number of oxygen defects as crystallite size decreases—at very small sizes, as many as 10% of the oxygen sites in the fluorite structure crystallites will be vacancies, resulting in exceptionally high diffusion rates.


Question And Answer

Get Prices

Answers to your queries


Buying Tip- See what like buyers had to say!



SUBMIT