Autocatalysts: Characteristics
Why the first cold minutes decide a catalyst's worth
Why the first cold minutes decide a catalyst's worth What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.What sells is conversion efficiency after ageing, light-off temperature at cold start, back-pressure and grams of PGM per vehicle. Durability to 160,000-200,000 km under Euro 7 is now a design requirement (indicative).
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| PGM loading | typically 2-7 g per light vehicle (indicative) | main cost | indicative |
| Light-off temperature | about 200-300 C for 50% conversion (indicative) | cold-start emissions dominate test cycles | indicative |
| Cell density | 400-900 cells per square inch (indicative) | surface area versus back-pressure | indicative |
Commercial grades
- Close-coupled TWC
- Underfloor TWC
- Coated GPF
- DOC
- Catalysed DPF
- Cu-zeolite SCR
- Vanadia SCR
- Ammonia slip catalyst
- Motorcycle metallic catalysts