Regulating Steric Effect of Cobalt Corroles for Promoted Oxygen Electrocatalysis

Regulating catalyst steric effects is commonly used in
organic
chemistry but is relatively much less explored in O2 activation.
Herein, we report on the steric effect of Co corroles on O2 reduction. Three Co corroles with different meso-substituents to regulate steric effects were synthesized. With bulky meso-substituents, Co corroles became more efficient, from
both thermodynamic and kinetic points of view, to bind and activate
O2. We confirmed that upon O2 binding, the resulted
superoxo unit can be stabilized due to the steric protection of bulky meso-substituents. With this improvement, Co corrole with
bulky meso-substituents displayed significantly improved
oxygen electrocatalysis.