We further examine our proposed EC'D mechanism by benchmarking the oxygen reduction performance of select metal-free OMIECs as well as glassy carbon, which is the underlying substrate for these measurements and reduces oxygen through an outer-sphere pathway (Figure ). The polymers chosen were p(NDI-T) , p(gPyDPP-MeOT2) , and p(g3T2) (Figure ). Fit E 0 1 First, we employ p(NDI-T) , which can be reduced to its electron polaronic state at voltages more positive than 𝐸 𝑂 2 𝑂 2 •- ⁄ 0′