Table 1. Catalyst Reduction Potentials (vs Ferrocene/Ferrocenium, Fc+/0), ORR Overpotentials (See Text), and TOF from FOWAa.
| catalyst | EFe(lll/ll) (V) | η Fe/ORR (V) | TOF (s–1) |
|---|---|---|---|
| 1ACN | –0.375 | 1.21 | 2.2 × 106 |
| 2ACN | –0.390 | 1.24 | 2.2 × 106 |
| 9ACN | –0.326 | 1.15 | 6.5 × 104 |
| 10ACN | –0.296 | 1.13 | 2.2 × 104 |
| 11ACN | –0.280 | 1.11 | 2.2 × 102 |
| 1DMF | –0.630 | 1.18 | 2.0 × 103 |
| 2DMF | –0.611 | 1.16 | 2.5 × 103 |
| 3DMF | –0.547 | 1.10 | 1.6 × 102 |
| 4DMF | –0.536 | 1.09 | 1.8 × 102 |
| 5DMF | –0.530 | 1.08 | 2.7 × 101 |
| 6DMF | –0.491 | 1.04 | 5.0 × 100 |
| 7DMF | –0.486 | 1.04 | 1.5 × 101 |
| 8DMF | –0.362 | 0.91 | 3.0 × 100 |
a
In ACN (superscript “ACN”) or DMF (superscript “DMF”), 0.1 M [Bu4N]PF6, 1 atm of O2, 20 mM [DMF-H]OTf, 100 mV/s scan rate. Experimental uncertainties are ±5 mV for EFe(III/II), ±20 mV for overpotentials, and ±15% for TOFs.