Text: It usually happens at night… lllustration: Thief wearing balaclava mask and holding large serrated blade eyes SUV parked in front of buildings at nighttime.
Text: Theft of catalytic converters — those bulbous contraptions on the underside of a car that remove noxious gases from the exhaust — has been on the rise across the U.S. Illustration: Graphic chart shows upward trend line, indicating rise in thefts from 2018 to 2020, with 2,347 thefts in December 2020 alone. In foreground, a catalytic converter.
Text: The thief can get up to a few hundred dollars from a scrapyard. Illustration: In a scrapyard, thief in balaclava counts cash in hand after handing catalytic converter to scrapyard owner, who wears cap with word “scrap” on it. Text: Victims get a car that sounds like a hot rod and a repair bill that can exceed $1,000. Illustration: Green car in mid-air, with wheels askew, and orange explosion and gray cloud coming out of back. Behind wheel is driver with eyes bulging in surprise.
Text: But catalytic converters have been around for nearly 50 years. So why is this happening now? The economic downturn caused by the pandemic might be one factor. Another is the soaring price of the precious metals that put the catalyst in catalytic. Illustration: Red trend arrow points downward, indicating economic downturn; green trend arrow points upward, indicating soaring price of precious metals.
Text: One of them, rhodium, hit $29,800 per troy ounce earlier this year, about 17 times the price of gold.
Text: These so-called platinum group metals help rid car exhaust of nitrogen oxides — which contribute to acid rain and smog — and deadly carbon monoxide. Catalytic converters were inverted in the 1950s, and have been widely used in American cars since 1975 to meet clean air standards. Illustration: Car, with smiling driver behind wheel and exhaust fumes billowing behind, travels along waterfront road lined with palm trees as sun sets on horizon.
Text: A catalytic converter is a marvel of chemical engineering. Illustration: Bruce Gates, chemical engineer, University of California, Davis, says, “It’s one of the great technological advances of the 20th century.” (Flytzani-Stephanopoulos, M. and Gates, B.C. Atomically Dispersed Supported Metal Catalysts, Annual Review of Chemical and Biomolecular Engineering, 2012).
Text: Inside a catalytic converter, exhaust flows throw a honeycomb structure speckled with tiny particles of one or more of these platinum group metals: platinum, palladium and rhodium. Oxygen sensors help keep the air-fuel ratio in a narrow range that optimizes the desired reactions. Chemistry 101 refresher: A catalyst accelerates a chemical reaction, but isn’t consumed or produced in the process. Illustration: Diagram of catalytic converter, with red arrow indicating input at one end and green arrow indicating input at other end. Middle section shows partial cross-section to reveal inner layers. Inset closeup image indicates inner layer with honeycomb structure, with red and blue particles moving within.
Text: The chemical reactions that take place inside a catalytic converter are called oxidation and reduction reactions. Some chemical bonds break and some form, creating different molecules in the process. Multiple reactions take place, and the end result is that environmentally unfriendly compounds — hydrocarbons (from unburned fuel), nitrogen oxides and carbon monoxide — get converted into harmless nitrogen, water and carbon dioxide. (Yes CO2 contributes to climate change but it’s not toxic in the short term like CO.) Illustration: Seen from rear, gray car’s exhaust pipe emits gray fumes, with drawings of molecules and chemical equations written in red, blue and orange. The equations read “2CO+2NO (arrow) 2CO2+N2,” “2H2+2NO (arrow) 2H2O+N2” and “HC+NO (arrow) CO2+H2O+N2.”
Text: The chemical reactions that take place inside a catalytic converter are called oxidation and reduction reactions. Some chemical bonds break and some form, creating different molecules in the process. Multiple reactions take place, and the end result is that environmentally unfriendly compounds — hydrocarbons (from unburned fuel), nitrogen oxides and carbon monoxide — get converted into harmless nitrogen, water and carbon dioxide. (Yes CO2 contributes to climate change but it’s not toxic in the short term like CO.) Illustration: Seen from rear, gray car’s exhaust pipe emits gray fumes, with drawings of molecules and chemical equations written in red, blue and orange. The equations read “2CO+2NO (arrow) 2CO2+N2,” “2H2+2NO (arrow) 2H2O+N2” and “HC+NO (arrow) CO2+H2O+N2.”
Illustration: Chemical engineer Bruce Gates is speaking, saying, “What’s remarkable about the catalytic converter is it does both oxidation and reduction at the same time in the same place.” Thief in balaclava mask peeks from behind and asks, “Is that unusual?” Then Gates replies, “Hell yes!”
Text: The catalytic chemistry of platinum group metals is complicated, but cheaper metals don’t work nearly as well. Their expense is largely due to their scarcity in the Earth’s crust — just 0.5 parts per billion in the case of platinum. Illustration: Economist Rod Eggert of Colorado School of Mines, in blue shirt and brown jacket, points at diagram showing Earth’s crust and says, “The platinum group elements tend to be found together in the same mineral deposits geologically. Rhodium usually is present in lower concentrations than platinum and palladium.” (Eggert, R. et al. Rare Earths: Market Disruption, Innovation, and global Supply Chains, Annual Review of Environment and Resources, 2016)
Text: About 90% of platinum group metals extracted since 1900 have come from South Africa and Russia. In 2019, global production of rhodium was less than 24 metric tons, compared to 189 tons of platinum and 3,300 tons of gold. About 80% of the world’s palladium and rhodium is used in catalytic converters, and demand could increase in the coming years as countries — especially China — implement stricter emissions controls. Illustration: Three transport trucks of different sizes transport metals. Largest is labeled “GOLD,” medium is “PLATINUM,” and tiny one is “RHODIUM” hitched with a much larger trailer carrying a giant catalytic converter.
Text: About 90% of platinum group metals extracted since 1900 have come from South Africa and Russia. In 2019, global production of rhodium was less than 24 metric tons, compared to 189 tons of platinum and 3,300 tons of gold. About 80% of the world’s palladium and rhodium is used in catalytic converters, and demand could increase in the coming years as countries — especially China — implement stricter emissions controls. Illustration: Three transport trucks of different sizes transport metals. Largest is labeled “GOLD,” medium is “PLATINUM,” and tiny one is “RHODIUM” hitched with a much larger trailer carrying a giant catalytic converter.
Text: The long-term outlook isn’t as clear. “I think platinum metal group producers are very concerned about the decline and shrinking of their market as a results of the transition to electric vehicles, which will not need catalytic converters.” Illustration: Economist Rod Eggert speaks about market decline of platinum metals.
Text: But that decline might partly offset by electric vehicles powered by hydrogen-fuel cells, which also use platinum group metals as catalysts. In the meantime, recycling (legitimate or otherwise) is an important source of these precious metals. In recent years, it has accounted for roughly a quarter of the supply. Illustration: Image of smiling driver in electric vehicle with bursts of blue coming out of wheels as it travels along coastal road.
Text: So how does the black market for catalytic converters work?
Text: Ben Stickle studies metal scavengers and thieves for his PhD. Many had at least some college education and had worked with metal as a mechanic, electrician or other tradesman or assistant. Illustration: Criminologist Ben Stickle of Middle Tennessee State University, in light blue shirt and sky blue jacket, sits by desk with books behind and framed photo of person in graduation cap, suit and tie, and balaclava mask, holding rolled-up diploma. Stickle is saying, “Almost all of them had at some point in their lives worked in an industry where they understood the value of metal.”
Text: Thieves sometimes sell their stolen good directly to a scrapyard. Illustration: Thief in balaclava mask offers a catalytic converter to scrap seller in blue overalls, red cap with word “scrap” and cigar. Text: Often, though, they sell to an intermediary. Text: In the case of catalytic converters, that could be someone like a mechanic’s assistant who mixes stolen converters in with ones acquired legitimately. Illustration: Mechanic with red hair and wrench tucked behind ear, wearing blue overalls, looks sideways slyly while he holds stolen catalytic converter near pile of catalytic converters labeled “new.”
Text: Catalytic converter thefts are an interesting test case for situational opportunity theories of crime, which focus on the physical and social factors that create opportunities for a certain type of crime, rather than on the motivations of the offenders. Illustration: Criminologist Pamela Wilcox of Penn State University, wearing black shirt, yellow jacket and eyeglasses, is saying, “It’s a branch of criminology that focuses on how the environment leads to crime, and therefore how it can be used or altered to reduce crime.” (Wilcox, P. and Cullen F.T. Situational Opportunities of Crime, Annual Review of Criminology, 2018)
Text: That typically means taking steps to make the crime harder… riskier… or less rewarding. Illustration: Thief wearing purple balaclava mask, brown jacket and blue pants, in various challenging situations: carrying lots of tools, wearing handcuffs, looking sadly into an empty wallet.
Text: So, for instance…
Text: Better lighting and surveillance cameras in parking garages. Illustration: Thief in purple, balaclava mask, brown jacket, blue pants and purples gloves stops in front of security camera in open-air parking lot at nighttime.
Text: Having a mechanic install a metal plate to make your car’s catalytic converter harder to remove—and pressuring manufacturers to add them to new cars. Illustration: Thief in brown jacket and purple balaclava mask and gloves shakes fist and looks angrily at metal padlocked security plate underneath car.
Text: Laws — like those on the books or pending in many states — that require sellers to show ID for scrapyard transactions. Illustration: Nervous-looking thief, with beads of sweat coming off head, in brown jacket and purple balaclava mask and gloves holds out ID card with photo and name “Stealy McCrime.”
Text: But because metal thefts often involve a middleman who fences the stolen goods for the person who stole them, Stickle doubts such laws will be effective. Illustration: Criminologist Ben Stickle is saying, “As with any market we would try to regulate out of existence, there’s multiple ways to get around it. Laws only work on those who obey them.”
Text: Another idea would be to require scrapyards to adopt the type of real-time tracking that pharmacies in some states use to flag suspicious purchases—like someone visiting one store after another to buy Sudafed, which can be used to make the illegal stimulant methamphetamine. Illustration: Nervous-looking thief in purple balaclava mask and gloves and brown jacket, carrying two catalytic converters approaches a show window with man in lab coat behind counter. It is criminologist Ben Stickle saying, “It would bring attention from law enforcement to the facilities making more risky purchases. I think that would be really, really helpful.”
Text: In the meantime, catalytic converter thefts are giving many people a big headache: an unexpected and expensive bill to replace something they barely knew was there. Illustration: Woman in green shirt looks annoyingly at invoice outside mechanic’s garage, as thief in purple balaclava mask and gloves, brown jacket and shoes, and blue pants sneaks off on tiptoe, carrying catalytic converter.

This piece was produced in cooperation with the Nib