Science Buddies: "Ask an Expert"

I am planning to do the Fuel Cell Efficiency Science Fair Project. I wanted my experiment problem statement to be based on how the fuel cell efficiency differs based on the type of catalyst, as suggested in the 'variations' tab. After possibility previewing the experiment, could any person with the knowledge suggest some catalysts that can be safely be reacted with 0.1M phosphate buffer, water, and nickel electrodes as seen in the given experiment?