Rhodium

Rhodium is one of the rarest metals from the platinum group, found in very small quantities in the earth′s crust (0.2 parts per billion). Rhodium’s chemical properties are related to its unusual ground state valence electron configuration in which it has only one electron in its outermost s orbital. This electron configuration has important implications for its catalytic ability, which has made rhodium useful in catalytic converters for automobiles. At the same time, metallic rhodium is a noble metal, meaning it has outstanding resistance to oxidation.

The powder form of rhodium is a silvery-grey and is used not just in the auto industry, but also in other areas like chemical synthesis and powder metallurgy. Rhodium is harder and melts at higher temperatures than both platinum and palladium, which makes it’s a useful hardening element in alloys. Additionally, it is popular for coating jewelry and other items because it gives a shiny, protective layer that does not easily wear away.

Rhodium can be used in the following applications:

• Rh supported on activated carbon (Rh/C) can be used as an efficient oxygen reduction reaction catalyst for the fabrication of microbial fuel cells.
• Used as a catalyst in the hydrosilylation of aromatic nitriles to N, N-disilylamines.
• Used to prepare Rhodium-Iridium alloy.