Transcription

Andrew Robinson: It is the most precious metal on the planet.

More valuable than silver, gold, platinum or even these jewels.

It’s that powder here.

This jewel is treated with a thin layer of rhodium, a chemically inert and corrosion resistant metal. It protects the silver and gives it a nice shiny finish.

But you probably use rhodium every day for another reason.

Rhodium has been a key ingredient in every car sold in the United States since about 1975.

It’s part of a system that cleans up pollutants and keeps them out of the atmosphere.

And that’s also why thieves across the United States are cutting catalytic converters in order to get their hands on a few precious grams of the world’s most precious metal.

So how did we get there?

Well in the 1970s the air in America was getting dirty.

And a big reason was automobiles.

Massive public pressure led the US Congress to pass the Clean Air Act of 1970, establishing national standards for air quality.

One of the goals of these standards was to reduce harmful emissions from automobiles, in particular a 90 percent reduction in automobile emissions from pre-1968 levels by the 1975 model year.

Engineers and researchers from Engelhard Industries and Corning Glassworks eventually developed what is the modern three-way catalytic converter.

The converter itself is located just behind the exhaust manifold and before the muffler.

Its objective: to reduce 3 types of harmful emissions: carbon monoxide, hydrocarbons (or unburned fuel) and nitrous oxides.

The converter on regular fuel vehicles is simple: a stainless steel shell surrounds a ceramic honeycomb monolith, this monolith is coated with three important precious metals: platinum, palladium and rhodium.

When the car’s exhaust passes through this honeycomb, the metals heat up and act as catalysts: turning carbon monoxide into carbon dioxide, unburned hydrocarbons into H₂0 and C0², and nitrous oxides to nitrogen and carbon dioxide.

Because these metals, and in particular rhodium, are so stable and durable that they can perform this function for an extremely long life of the auto part, with very little loss of performance.

But as effective as rhodium is at catalyzing car exhaust gases, it has one major drawback: cost.

These are called precious metals for a reason.

Morris Bullock: Precious metals are the very expensive ones and they are expensive because they are scarce – that is, they have a low abundance from Earth.

Thus, the precious metals include the metals of the platinum group which are ruthenium, rhodium, palladium, platinum, osmium and iridium but also the precious metals include other metals more known to the public such as gold and silver.

Just to give you an example, rhodium which is one of the metals used in catalytic converters, the earth’s abundance is in the range of 1 part per billion. Iron, for example, the Earth’s abundance is about 5 percent.

Robinson: So if rhodium has always been scarce, why are the prices going up now?

Closed mines and refineries created a huge supply shortage for rhodium, palladium and platinum even as demand increased worldwide

It’s a perfect storm that’s creating a huge spike in the prices of all these precious metals and especially rhodium.

Due to this deficit, rhodium prices peaked in March 2021.

And if automakers can’t buy these metals in the mines, they’ll find them elsewhere: recycling.

Recycled platinum group metals make up a large portion of the group’s precious metals used by U.S. automakers, which means it’s big business. This business translates into an opportunity on the street:

But preventing these thefts is a challenge …

S. Bruce Hosea: It is no longer violent crimes, it is no longer crimes against people that transform them from the status of violent crime to that of property crime. Resources cannot be allocated to property crimes in the same way they are given attention to violent crimes. And without specific markings on the catalytic converters themselves, there is no way to tell if Cat 1 vs Cat 2 has come out of your car or someone else’s car.

Robinson: Being environmentally friendly can also come at a cost.

Yong Wang: When you think of a hybrid, the engine is not turned on all the time so the temperature is even lower. So what are you doing? With the existing technology, you just put in more catalysts, you have to put in more Rhodium and that equates to a huge shortage.

Robinson: So what can we do? Electric vehicles are a solution because they have no exhaust at all

Wang: If you look at light commercial vehicles, in the world we have a billion vehicles in this industry and it is expected to double by 2040. To replace all of these vehicles with batteries, it will not happen overnight.

Robinson: Decreasing our dependence on these metals will not only reduce the demand for thieves, but it will also help the environment.

Beef: We are carrying out many fundamental scientific studies on how to design new catalysts based on metals abundant on earth like iron or nickel for reactions which are currently catalyzed by precious metals.

Robinson: Until then, rhodium will remain in our cars and be a potential target for thieves, seeking to profit from the most precious metal in the world.