Rhodium

Rhodium is a chemical element; it has symbol Rh and atomic number 45. It is a very rare, silvery-white, hard, corrosion-resistant transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isotope, which is 103Rh.

It reduces nitrogen oxides in exhaust gases. Rhodium is also used as catalysts in the chemical industry, for making nitric acid, acetic acid and hydrogenation reactions. It is used to coat optic fibres and optical mirrors, and for crucibles, thermocouple elements and headlight reflectors.

Hydrogen

Identity.

Rhodium is a member of the platinum group of metals and is silver-hued, highly reflective and does not tarnish or corrode. It is harder than gold and is highly durable. If you see the stamp, and the ring is silver-colored, it's rhodium-plated.

History.

Rhodium, a rare and valuable metal, was discovered in 1803 by English chemist William Hyde Wollaston. He obtained it from a sample of platinum ore that originated in South America. While trying to purify platinum, Wollaston noticed a red residue that remained after various chemical treatments. This residue turned out to be a compound containing rhodium.

Wollaston named the new element "rhodium" after the Greek word for "rose," referring to the rose-red color of some of its compounds. For many years, rhodium had limited uses due to its rarity. However, its unique properties, such as high resistance to corrosion and excellent catalytic abilities, eventually led to its widespread application in various fields.

Paracelsus

Usage.

  • Catalytic converters: This is the primary use of rhodium, accounting for over 80% of global demand. Rhodium acts as a catalyst in converters, reducing harmful pollutants like nitrogen oxides from vehicle exhaust emissions.
  • Chemical catalysts: Rhodium plays a crucial role in various chemical reactions, including the production of nitric acid, acetic acid, and hydrogenation processes.
  • Jewelry: Rhodium plating is used on white gold and silver jewelry to enhance their shine and tarnish resistance.
Some of the benefits of using rhodium are:
  • In catalytic converters, rhodium helps convert harmful pollutants in car exhaust into less harmful substances, contributing to cleaner air.
  • As a catalyst, rhodium enables various chemical reactions to occur more efficiently, potentially leading to reduced waste and energy consumption in some industrial processes.
  • Rhodium alloys can withstand extreme temperatures, making them suitable for demanding applications.

Sources.