Palladium is a rather expensive metal, being in the platinum group. Current Primary use is in catalytic converters for automobiles.
https://en.wikipedia.org/wiki/Palladium
Of course if we are all driving electric cars then it won’t be necessary.
Once the cold fusioneers get to a reproducible-on-demand anomalous effect, the smart folks will look through all those Hydrogen-Nickel LENR results and it’ll be much more cost effective. Besides, it’s the hydrogen that is the fuel, not the Palladiumn/Nickel.