Autocatalysts
Exhaust catalysts coated with platinum, palladium and rhodium that clean car and truck exhaust; the largest use of platinum-group metals.
Specialty chemicals · Catalysts · No. 75
- Product family
- Feedstock: Minerals and salts
- about 378 t of PGMs a year in vehicle catalysts (2025): palladium 256 t, platinum 95 t, rhodium 28 t
- 0.1 t CO₂e per t
- HS 381512
A few grams of platinum, palladium and rhodium clean each car's exhaust, and vehicles soak up 378 t of them a year.
Chart: Illustration: Autocatalysts
Where it comes from
Chart: Map of where it comes from
South Africa mines about 70% of the world's platinum and about 81% of its rhodium; coaters spread these metals on ceramic honeycombs.
Three things to know
- Palladium is the biggest metal by mass, about 256 t a year, mostly in petrol three-way catalysts.
- Primary platinum emits about 36,828 t CO2e per tonne, recycled platinum about 477 t, so recycling cuts the footprint dramatically.
- India's BS-VI rules since April 2020 put catalysts on every new vehicle, including two-wheelers, using imported metal.
The journey
- 1 PGM minesMostly South Africa and Russia
- 2 HoneycombCeramic with 400-900 cells per square inch
- 3 WashcoatAlumina and ceria slurries carrying PGM salts
- 4 Exhaust systemCleans CO, hydrocarbons and NOx
- 5 Scrap recyclingSpent converters refined for their metals