But the violation of marriage, or any other unchastity, was never heard of; and the married pair pass their lives with the same friendship and mutual benevolence, that they bear to all others of the same species who come in their way, without jealousy, fondness, quarrelling, or discontent.
The catalyst used in the converter is mostly a precious metal such as platinum, palladium and rhodium. Platinum is used as a reduction catalyst and as an oxidation catalyst. Although platinum is a very active catalyst and widely used, it is very expensive and not suitable for all applications.
That's the job that a catalytic converter does. These gadgets are much simpler than they sound. A catalyst is simply a chemical that makes a chemical reaction go faster without itself changing in the process. It's a bit like an athletics coach who stands by the side of the track and shouts at the runners to go faster.