Every time a car burns fuel, combustion is never perfect. Along with carbon dioxide and water vapor, very harmful gases appear such as carbon monoxide or nitrogen oxides. They not only affect the lungs and the heart, they also cause acid rain and destroy entire ecosystems.
The solution came in the 70s with an invention that changed automotive forever: the catalytic converter. A piece the size of a shoebox that, thanks to rhodium, platinum and palladium, manages to reduce up to 99% of toxic emissions.
How does a catalytic converter work
The process is divided into two very clear phases. First, nitrogen oxides pass through an area with rhodium and platinum, which separates the oxygen and converts them into nitrogen and oxygen, two harmless gases that are part of the atmosphere.
Then comes the oxidation part. The gases pass through another section with platinum and palladium, where carbon monoxide and unburned hydrocarbons are transformed into carbon dioxide and water. CO₂ is still a greenhouse gas, yes, but much less toxic than the original compounds.
This way, each car trip is a little cleaner and safer thanks to this small device.
An invention that saved millions of lives
Before they existed, large cities were covered in smog. In the 60s and 70s, places like Los Angeles or Mexico City lived with pollution that skyrocketed respiratory diseases.
The introduction of catalytic converters, and later the obligation to install them in all cars, changed the air in cities. According to the United States Environmental Protection Agency (EPA), concentrations of carbon monoxide and nitrogen oxides in urban air fell by more than 70% in a few decades.
It is not an exaggeration to say that this small component has prevented millions of premature deaths. And today, although electric cars are gaining ground, it is still essential in gasoline and hybrid cars that drive all over the world.
Why are they so valuable
The key of the catalytic converter is not only how it works, but the rare metals that make it possible. Rhodium, palladium and platinum are scarce and extremely expensive materials. In 2021, rhodium reached a cost ten times higher than gold, and although it has dropped now, it still doubles its price. Platinum and palladium, on the other hand, are around a third of the value of gold.
Each catalytic converter carries only a few grams, but enough for the black market to pay a more than attractive amount.
The boom of catalytic converter theft
With these prices, catalytic converters have become one of the most stolen car parts. The method is fast: in a few minutes, thieves get under the vehicle, cut it and take it away.
For the owner, the hit is double: he loses a very expensive part and, on top of that, the repair usually goes over 1,000 euros.
In cities like Madrid, London or New York, the police have dismantled entire gangs dedicated only to this business. The metals are extracted, resold in clandestine markets or melted to export them. Only in the United States, in 2022 more than 150,000 catalytic converter thefts were reported, 1,200% more than five years earlier.
The paradox of the catalytic converter
The catalytic converter is one of the most important inventions of recent history. It has saved lives and improved air quality worldwide. But its own value has turned it into a magnet for the black market.
The paradox is clear: a piece designed to protect the planet has become the Achilles heel of millions of cars.
The hidden treasure in the exhaust
Every time you start your car, under the chassis you carry hidden metals more valuable than gold. Their function is to reduce emissions and protect your health, but at the same time they make them a target for thieves.
The challenge now is to find ways to make them safer without losing effectiveness. Because, although many do not know it, the best kept secret of a car is not in the engine, but in the exhaust.