Development of Reversal-tolerant Catalyst Layers

To study and resolve the voltage reversal problem, a Mn02-Pt/C composite electrode was used by Wei et al. [33] to replace the conventional Pt/C electrode. This choice was based upon the fact that the electrochemical reduction of Mn02 has almost the same Nemstian potential as the ORR, as shown below  

The reaction in Equation 17.7 can replace the ORR in the case of oxygen starvation. Thus, the voltage reversal effect (VRE) resulting from the proton reduction reaction (PRR) could be avoided without the use of a fan to scavenge the excess water. Two environments, N2- and 02-saturated H2SO4, were adopted to simulate two cases, i.e., O2 starvation and O2 richness. It was found that Mn02-Pt/C can prevent the voltage reversal effect to a certain extent. In a N2-saturated 

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