Nickel iron oxide is the best catalyst for a type of fuel cell based on Anionic Exchange Membranes. Cheap as dirt and you only need milligrams per kW. But it's

Nickel iron oxide is the best catalyst for a type of fuel cell based on Anionic Exchange Membranes. Cheap as dirt and you only need milligrams per kW. But it's so cheap you can use a tenth of a gram just to be on the safe side.