# Autocatalysts

Exhaust catalysts coated with platinum, palladium and rhodium that clean car and truck exhaust; the largest use of platinum-group metals.

Source page: https://www.materialinsights.org/chemicals/autocatalysts/

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
 Specialty chemicals · Catalysts · Foundation · Matter

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

1. Palladium is the biggest metal by mass, about 256 t a year, mostly in petrol three-way catalysts.
2. Primary platinum emits about 36,828 t CO2e per tonne, recycled platinum about 477 t, so recycling cuts the footprint dramatically.
3. India's BS-VI rules since April 2020 put catalysts on every new vehicle, including two-wheelers, using imported metal.

##### The journey

1. 1 **PGM mines**Mostly South Africa and Russia
2. 2 **Honeycomb**Ceramic with 400-900 cells per square inch
3. 3 **Washcoat**Alumina and ceria slurries carrying PGM salts
4. 4 **Exhaust system**Cleans CO, hydrocarbons and NOx
5. 5 **Scrap recycling**Spent converters refined for their metals

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## Other sections

- [Overview](https://www.materialinsights.org/chemicals/autocatalysts/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/autocatalysts/correlation/index.md)
- [Production route](https://www.materialinsights.org/chemicals/autocatalysts/routes/index.md)
- [Production](https://www.materialinsights.org/chemicals/autocatalysts/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/autocatalysts/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/autocatalysts/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/autocatalysts/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/autocatalysts/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/autocatalysts/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/autocatalysts/characteristics/index.md)
- [Emissions](https://www.materialinsights.org/chemicals/autocatalysts/emissions/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/autocatalysts/links/index.md)