You see, a metal shouldn't be able to do what this "electrum" could do. No compound of gold and silver could make the dead Talons walk again... 
Electrum is a metallic alloy that, when prepared in the correct way, has the ability to reanimate the dead and beqeath mild regeneration.
History
The Court of Owls learned to use the metal from Doctor Leviticus centuries ago to save and reanimate their Talons over generations. The bodies of the Talons were specifically prepped so that they would reanimate in a matter of minutes if touching a piece of Electrum, usually in the form of a metal tooth implant. This process was further perfected in the modern day by Mister Freeze, who hadn't realized he was working for the Court but, instead, was told he was working towards the downfall of Batman.[1]
Electrum was one of the five metals that, when one person was exposed to them all, would open a portal to the Dark Multiverse. Batman, having been primed for the ritual, was unknowingly exposed to Electrum when he was trapped in the Court of Owls' Labyrinth and forced to drink from their fountain.[2]