What Type Of Metal Is In A Catalytic Converter? [ Here’s The List ]

Although the catalytic converter doesn’t really play a role in helping your car run, it’s one of the most expensive components. The average price of a catalytic converter can be anything between USD 500 and USD 2500, but even cost more than USD 3000 in some cases.

This is because the component contains precious metals which have high value even as scrap. It also makes the catalytic converter a very common target for theft. In fact, catalytic converters are the most stolen car part in the US.

What type of metal is in a catalytic converter?

A catalytic converter contains platinum, palladium, and rhodium, all of which are precious metals. All three are members of the platinum group of metals, and are among the rarest metals on earth.

These metals are present in the form of a coating over the ceramic honeycomb of the catalytic converter. The exhaust gasses passing through the cat converter come in contact with them. Besides these three precious metals, other metals like iron, copper, cerium, nickel, and manganese are present in catalytic converters too.

Platinum, palladium, and rhodium are powerful catalysts that cause toxic gasses in the exhaust fumes to react and break down into less dangerous substances.

This plays a huge role in reducing car emissions, so it is mandatory to have a catalytic converter installed in your car. Here’s a brief overview of the three metals and how they work:

1. Platinum

This silvery-white metal is much rarer than gold, and hence more expensive. It boasts high thermal durability and corrosion resistance, which make it perfect for catalytic converters. Although the exhaust gasses are very hot and contain reactive substances, their effect on platinum is negligible.

Platinum plays a major role in the reduction of nitric oxide. Together with rhodium, platinum removes the nitrogen molecules and holds them, while releasing the oxygen molecules.

The nitrogen molecule will bind to other nitrogen molecules and exit the exhaust together. Thus, platinum breaks down the nitric oxide, which is poisonous, into harmless nitrogen and oxygen gas.

While platinum acts as a reduction catalyst for nitric oxide, the metal also functions as an oxidation catalyst for hydrocarbons and carbon monoxide.

When carbon monoxide and hydrocarbons pass through the platinum-coated area of the catalytic converter coated, they react with oxygen molecules. Platinum, as a powerful catalyst, facilitates the reaction and helps in the formation of carbon dioxide and water vapor from these toxic substances.

2. Palladium

While platinum helps in all the major reactions in a catalytic converter, palladium is much more effective. In some cars, palladium helps in breaking down around 90% of the harmful substances in the emissions.

Palladium shares several similarities with platinum, such as the silvery white color and high melting point. However, palladium is more susceptible to corrosion as compared to platinum.

Palladium helps primarily in the oxidation of carbon monoxide and hydrocarbons, and is therefore, an oxidation catalyst. Like platinum, palladium is present in both petrol and diesel catalytic converters. Although palladium isn’t as rare as platinum, it is still more expensive.

3. Rhodium

Among the three precious metals you’d find in a catalytic converter, Rhodium holds the highest value. In fact, rhodium happens to be the rarest metal on earth and is consequently the most expensive.

Due to the high cost and difficulty to obtain rhodium, some catalytic converters may contain only trace amounts of the metal. Diesel cat converters do not have any rhodium at all, which is why they are far cheaper than petrol catalytic converters.

Although rhodium has other purposes too, around 90% of the global rhodium demand comes from the automotive industry to manufacture catalytic converters.

The primary purpose of rhodium in a catalytic converter is to help reduce nitric oxide into nitrogen and hydrogen. This metal is extremely effective as a catalyst for this reaction, which is why it’s crucial to use rhodium despite its high cost.

Rhodium is many times costlier than platinum or palladium. Hence, a majority of a catalytic converter’s scrap value usually comes from rhodium. This is the reason behind the huge cost difference between petrol and diesel cat converters, as the latter doesn’t contain any rhodium.

What is in a catalytic converter that is so valuable?

As mentioned earlier, the high value of a catalytic converter mostly comes from the three precious metals contained inside. However, the metals are present in really small amounts – about three to seven grams of platinum and palladium each, and potentially up to 10-12 grams in certain cars.

As for rhodium, most catalytic converters have only 1-2 grams of this metal. This might make you wonder why this component holds such high scrap value, if the quantity of precious metals is so little.

Well, for a better understanding, you first need an idea of how much the three precious metals cost. Currently, a gram of palladium costs USD 60, a gram of platinum is worth USD 27, and rhodium costs USD 450 per gram.

Right there, you have your answer. An average catalytic converter with two grams of rhodium, five grams of platinum, and five grams of palladium would fetch a scrap value of around USD 1300.

Hence, although the metals are present in very small quantities, their value is high enough to make catalytic converters one of the most expensive components in a car.

Conclusion

Although the three precious metals used in catalytic converters are very expensive, they are indispensable in reducing vehicle emissions. Considering the prices of platinum, palladium, and rhodium, it is only natural that catalytic converters are worth so much money.

However, while your old cat converter can fetch you a decent sum of money as scrap, a missing cat converter will cost even more to replace. This explains why you must be vigilant and take protective measures to deter thieves. It’ll be wise to install protective equipment and park your car in less vulnerable places.