In simple wood stoves, there is normally no fan, so the catalytic converter must not cause a significant pressure drop.
Another consideration is that ash will be present, which could block the channels in the catalytic converter.
For these two reasons, it is best to specify one based on a honeycomb substrate with a low cell-density, for example 18 or 25 cells per square inch.
The flue gas temperature in appliances which burn logs can vary significantly, which means that a substrate which can act as a heat store may be preferable.
In this respect, ceramic honeycombs are better than metal ones.