Three chemists - Jöns Jacob Berzelius, Wilhelm Hisinger and Martin Heinrich Klaproth - discovered cerium in 1803, though completely independently of each other. Cerium is a soft, silvery white, malleable and ductile metal, which oxidizes readily in air. In pure form, cerium can ignite if scratched: a property which is known as ‘pyromorphism’ and is utilized in lighter flints.
Cerium is primarily obtained through solvent extraction processes of light rare earth minerals such as bastnaesite.
Applications of Cerium:
- Glass and Ceramics: Cerium oxide is used to polish glass surfaces. Cerium compounds are used in the manufacture of glass and enamels, both as a component and as a decolourizer. Cerium oxide is also a component of the walls of self-cleaning ovens.
- Lighting: In LEDs, cerium combined with yttrium turns blue light into white light.
- Solar panels: Cerium oxide, in combination with tin oxide, is used for UV absorption in solar panels.
- Catalysts: Cerium oxide is used as a catalytic converter to reduce carbon monoxide emissions in the exhaust gases from motor vehicles. Cerium additives to diesel fuel enable the fuel to burn more cleanly, with less resulting air-pollution. Cerium oxide is also used as a petroleum cracking catalyst in petroleum refining.
- Alloys and Metals: Cerium is alloyed with iron to make nodular iron to improve automotive power-train components. It is added to magnesium alloys as a grain boundary modifier in magnesium, which improves thermal resistance and give sound casting of complex shapes. It is used in stainless steels as a precipitation hardening agent.
- Other Uses: Cerium is one of the rare earth elements used to make carbon arc lights, which are used in the film industry for studio lighting and projector lights.