Understanding the chemical process in a fuel cell

[JoJoQuinoa]

Hello,

I'm taking an energy class and I'll be giving a presentation on fuel cells. I was wondering if I could get some help understanding the whole process of the paper below. Unfortunately, I can't post the article because of copyrights. To summarize, it's a one compartment H2O2 fuel cell with Ag foil as the anode and Prussian Blue coated carbon paper as the cathode. The reaction is as follow:

Anode: H2O2 → O2 + 2H+ + 2e− ; Eo = −0.68 V
Cathode: H2O2 + 2H+ + 2e− → 2H2O ; Eo = 1.77 V
Total: 2H2O2 → 2H2O + O2

I am trying to understand the role of prussian blue in this setup. The paper mentioned that Prussian Blue acted as the catalyst for this reaction but I'm not sure which process they're referring to. Is the present of Prussian blue causes the H2O2 molecules to break down on the anode side or it is there to combine H2O2 with the ions to form water?

Thank you!

"A membraneless hydrogen peroxide fuel cell using Prussian Blue as cathode material"

 

[Ygggdrasil]

From the article:

Prussian Blue (PB) is a renowned catalyst for H2O2 reduction under acidic conditions and its electrocatalytic reduction of hydrogen peroxide for biosensing and analytical applications has been studied extensively.12,13

From reference #13:

https://www.sciencedirect.com/science/article/pii/S0956566304005883?via=ihub

 

[TeethWhitener]

I am trying to understand the role of prussian blue in this setup.

Prussian blue catalyzes the cathodic reduction of hydrogen peroxide to water. Without a catalyst, there is a kinetic barrier to peroxide reduction (this is referred to as an overpotential in electrochemistry). The larger the overpotential, the less efficient the fuel cell is, because energy is “wasted” getting the peroxide reactants over the activation barrier.

Edit: strictly speaking, the overpotential refers to the excess amount of voltage you need (above the half-reaction potential) to actually get the reaction to proceed. It corresponds directly to the kinetic activation barrier of the reaction.