Single Metal Atom Catalysts and ORR : H-Bonding, Solvation, and the Elusive Hydroperoxyl Intermediate

• 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.

Ämnesord

NATURVETENSKAP  -- Fysik -- Den kondenserade materiens fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Condensed Matter Physics (hsv//eng)

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

NATURVETENSKAP  -- Kemi -- Materialkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Materials Chemistry (hsv//eng)

Nyckelord

energy transfer

hydroperoxyl

oxygen reduction reaction

SFG

single-atom catalysts

solvation

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