User:VivaceBelles/cerium(IV) oxide

Sandbox for NSPN Wiki cohort 4 and developing cerium oxide (ceria)

Fuel efficiency nanoparticle use - talk about catalysis; reorganize and condense the sections on applications and research

Energy & fuels
Due to the significant ionic and electronic conduction of cerium oxide, it is well suited to be used as a mixed conductor. As such, cerium oxide is a material of interest for solid oxide fuel cells (SOFCs) in comparison to zirconium oxide.

Thermochemically, the cerium(IV) oxide–cerium(III) oxide cycle or CeO2/Ce2O3 cycle is a two-step water splitting process that has been used for hydrogen production. Because it leverages the oxygen vacancies between systems, this allows ceria in water to form hydroxyl (OH) groups. The hydroxyl groups can then be released as oxygen oxidizes, thus providing a source of clean energy.

Nanoceria has also been studied as a potential fuel additive, given that the stability of the nanoparticle can keep carbon oxidized, make fuel more economical. However, research studies have highlighted the additional respiratory concerns of long-term exposure of cerium and whether or not the lungs are able to remove cerium from the body efficiently.

Health
Cerium oxide nanoparticles (nanoceria) have been investigated for their antibacterial and antioxidant activity. While there are concerns about the general toxicity, the therapeutic potential to treat reactive oxygen species-related diseases such as Alzheimer's and cancer makes nanoceria an attractive alternative to current biomedical tools. The in vitro research evidence has concluded that nanoceria are safe nanoparticles in comparison to some of the in vivo studies, though many studies generally show the toxicity impacting damaged or diseased cells.

Nanoceria is a prospective replacement of zinc oxide and titanium dioxide in sunscreens, as it has lower photocatalytic activity.

Optics
CeO2 is used to decolorize glass by converting green-tinted ferrous impurities to nearly colorless ferric oxides.

Cerium oxide has found use in infrared filters, as an oxidizing species in catalytic converters and as a replacement for thorium dioxide in incandescent mantles

Polishing
The principal industrial application of ceria is for polishing, especially chemical-mechanical planarization (CMP). For this purpose, it has displaced many other oxides that were previously used, such as iron oxide and zirconia. For hobbyists, it is also known as "opticians' rouge".

Welding
Cerium oxide is used as an addition to Tungsten electrodes for Gas Tungsten Arc Welding. It provides advantages over pure Tungsten electrodes such as reducing electrode consumption rate and easier arc starting & stability. Ceria electrodes were first introduced in the US market in 1987, and are useful in AC, DC Electrode Positive, and DC Electrode Negative.