Science Buddies: "Ask an Expert"

Hello,

I've posted this in middle school forum, but I'll try here, seeing as this is a high school level concept.

My project this year relates to fuel cell catalysts (see right) and I've been doing research on the topic.

By looking at volcano plots of catalysts, I've figured out that the effectiveness of a fuel cell catalyst is determined by change in standard electrode potential of the catalysts (ΔEo). Δ Eo is equal to Eo(reduction) - Eo(oxidation). For platinum [the control], ΔEo = 1.18 - (-1.18) = 1.18 + 1.18 = 2.36 volts.

My question is: I want to know how to determine ΔEo for a compound, for example, aluminum fluoride which is AlF3. I'm thinking it might be something like:
ΔEo of AlF3 = ΔEo of Al + ΔEo of F
OR
ΔEo of AlF3 = (Eo reduction of Al + Eo reduction of F) - (Eo oxidation of Al + Eo oxidation of F).

Can you tell me the formula for ΔEo for a compound?
Thank you,
candy4me

Please help me with my question! I don't know how to figure this out.

What is the difference between ΔEo and Eocell? Is it the same?

I'm not an expert in this particular area, but I very much doubt that there is a general "formula" for the electrode potential of compounds. It probably has to be measured. That's certainly implied by the wikipedia page on the topic: http://en.wikipedia.org/wiki/Standard_e ... _potential, but at least there's a link in the middle of the page to a table of these values that might contain what you need.

I'm guessing that if you can't look it up, you'll have to measure it in a cell with a reference electrode.