| Přispěvatelé: |
Armillotta, Francesco, Bidoggia, Davide, Baronio, Stefania, Biasin, Pietro, Annese, Antonio, Scardamaglia, Mattia, Zhu, Suyun, Bozzini, Benedetto, Modesti, Silvio, Peressi, Maria, Vesselli, Erik |
| Popis: |
The widely investigated oxygen reduction reaction (ORR) is well-known to proceed via two competing routes, involving two or four electrons, and yielding different reaction products, respectively. Both pathways are believed to share a common, elusive intermediate, namely, the hydroperoxyl radical. By exploiting a cobalt single-atom biomimetic model catalyst, based on a self-assembled monolayer of Co-porphyrins grown on an almost free-standing graphene sheet, we identify, in situ at room temperature in O2+H2O atmosphere, a hydroperoxyl-water cluster that is stabilized at the Co single metal atom catalytic site. We show that the interplay between charge transfer, dipole and H bonding, and water solvation behavior actually determines the hydroperoxyl-water complex stability, the Co-OOH bonding geometry, and, prospectively, opens to the engineered control of the selectivity of ORR pathways. |
