The London Time s article on 21st November 2020 reported that the thefts of catalytic converters have increased significantly recently. The police had logged in 14,690 incidents across Britain this year, a rise from 2,484 a year earlier and 985 the year before. The rise is believed t have ben driven by a steep rise in the use of precious metals in catalytic converters. It has also been linked to the growth in popularity of hybrid cars, which tend to contain higher concentration of the precious of the precious metals, and 4 x 4s, whose higher chassis make is make easier for thieves. Criminals can remove the catalytic converter of car in less than a minute using an electric saw.
Precious metals in catalytic converters
A catalytic converter is a device used to convert toxic vehicle emissions to less toxic harmful substances by way of catalyzed, or accelerated chemical reactions. Most present-day vehicles that run on gasoline, including automobiles, trucks, trains, motorcycles and planes, have exhaust systems employing catalytic converters. The catalyst component of a catalytic converter is usually platinum (Pt), along with palladium (Pd), and rhodium (Rh). All the three platinum group metal or PMG are extremely rare but have a broad range of applications. In addition, to catalytic converter Platinum, for example, is used in laboratory and dental equipment, electrical contacts and electrodes, and jewellery, while Palladium plays a key role in fuel cell technology. With numerous applications, and limited supply these valuable metals are an attractive target for recovery and reuse from spent catalytic converters.
The amounts and proportions of PGMs depends on the age and type of vehicles.
- Car, light trucks, and motorcycles average total 2-6 grammes.
- Larger -engine SUVs and trucks average total can range anywhere from 6 -30 grammes.
Gasoline-powered -vehicle catalytic converters use all three of the rare-earth metals. Diesel-powered -vehicle catalytic converters use only platinum and rhodium.
The average concentration of and the ratio of Pt and Rh were more or less constant 20 years ago, so a simple weighting was sufficient to arrive at a good estimation of the precious metals content. However, the price of these three precious metals has fluctuated strongly over the last twenty years, depending on the supply, demand and speculation.
The Times London article noted that scrap metal dealers can pay up to BP200 per catalytic converter. The table below the value of the precious metals compared to other metals such as gold and gold.
|Metal||BP in gramme||BP in kilogramme|
The supply and demand for PMGs
Johnson Matthey, which produces a third of all catalytic converters in the world publishes the Pmg report annually. The latest report published in February 2020 shows the supply and demand situation in 2017, 2018 and 2919, respectively.
Platinum in thousand oz
|Total gross demand||7,994||7,788||8,484|
|Total net demand||5,945||5,690||6,223|
|Movements in stocks||194||420||-203|
Palladium in thousand oz
|Total gross demand||10,063||10,204||11,502|
|Total net demand||7,202||7,083||8,086|
|Movements in stocks||-751||-77||-1,192|
Rhodium in thousand doz
|Total gross demand||1,041||1,042||1,144|
|Total net demand||731||707||772|
|Movements in stocks||28||50||-26|
The prices of precious metals used in catalytic converters are likely to increase with the popularity of hybrid cars and newer efficient gasoline-cars. Their owners would have to be aware that the exhaust systems would be an open invitation to thieves, as their scrap values are high with every increase in the price of platinum, palladium and rhodium.