Chemistry
Most of a journey's pollution leaves the exhaust in the first two minutes, before the converter has woken up
2 Sept 2026 · 12 min read
A catalytic converter contains a few grams of platinum-group metal divided so finely that most of its atoms sit on a surface. It is a remarkable piece of nanoscale engineering that does nothing at all until it is hot — which is why short trips pollute far more than their distance suggests.
Read more →