Stuff You Should Know – Short Stuff: Rhodium

Intro

In this episode of “Stuff You Should Know,” hosts Josh and Chuck dive into the fascinating world of rhodium. They explore its discovery, rarity, and various uses, including its crucial role in catalytic converters and jewelry making.

Main Takeaways

Discovery and Rarity

• In 1800, William Hyde Walliston and Smithson Tennant discovered pure platinum, palladium, and rhodium in a platinum ore they purchased from what is now Colombia.
• They paid a significant amount of money for the ore, which was essentially pure platinum, as it was very hard to find.
• Walliston and Tennant discovered that rhodium and palladium were related to platinum and part of the platinum group metals.
• Rhodium is incredibly rare and found in minuscule amounts in alloys with other metals.

Value and Demand

• As of April 2021, the price of an ounce of rhodium was approaching $30,000, making it one of the rarest and most valuable precious metals.
• Rhodium’s demand has gone down due to the decline of catalytic converters, which use rhodium, because of the rise of electric vehicles.
• Catalytic converters contain palladium, platinum, and rhodium, making them targets for theft.
• Rhodium is effective at converting nitrous oxide emissions, making it a crucial component in catalytic converters.
• The solution to reducing nitrous oxide emissions is not more rhodium, but fewer catalytic converters.

Sources and Uses

• 80% of the world’s rhodium supply comes from South Africa, with Russia and Zimbabwe following behind.
• Rhodium is used in catalytic converters to reduce nitrous oxide emissions.
• Rhodium is a hard, shiny, and durable metal that is difficult to work with in jewelry making.
• Rhodium plating is hypoallergenic and scratch-resistant, making it popular for jewelry.
• Rhodium is also used as a catalyst in the production of menthol, found in chewing gum and mints.

Summary

The Discovery and Rarity of Rhodium

In 1800, William Hyde Walliston and Smithson Tennant made a significant discovery when they purchased a platinum ore from Colombia. They found pure platinum, palladium, and rhodium in the ore. Rhodium, part of the platinum group metals, is incredibly rare and exists in small amounts in alloys with other metals.

The Value and Demand for Rhodium

Rhodium has become one of the rarest and most valuable precious metals, with an ounce reaching nearly $30,000 in April 2021. However, the demand for rhodium has decreased due to the decline of catalytic converters, which use rhodium, as electric vehicles rise in popularity. Catalytic converters, containing rhodium, palladium, and platinum, have also become targets for theft.

The Sources and Uses of Rhodium

South Africa is the largest supplier of rhodium, accounting for 80% of the world’s supply. Russia and Zimbabwe also contribute to the production of rhodium. Rhodium plays a crucial role in catalytic converters, aiding in the reduction of nitrous oxide emissions. It is a hard and durable metal, making it challenging to work with in jewelry making. However, rhodium plating is popular for its hypoallergenic and scratch-resistant properties. Additionally, rhodium serves as a catalyst in the production of menthol, which is found in chewing gum and mints.

Conclusion

Rhodium’s rarity, value, and diverse uses make it a fascinating element in the world of precious metals. From its discovery alongside platinum to its role in reducing emissions and enhancing jewelry, rhodium continues to captivate scientists and enthusiasts alike.