3D Polymetallocorroles as Highly Efficient Catalyst for Oxygen Reduction

The worldwide effort of identifying/designing catalysts for energy relevant processes that are not based on precious metals has uncovered cobalt corroles as very potent electrocatalysts for the oxygen reduction to water, with quite impressive high selectivity and low overpotential. Of the various drawbacks that still prevent a larger breakthrough, the most serious one appears to be the limited coverage of the electrodes by hitherto utilized methodologies. We now report on the electropolymerization of a specifically designed cobalt corrole, cobalt(III)-tris(p-aminophenyl) corrole, on three types of electrodes: ITO for spectroscopic examinations, glassy carbon for further characterization, and high performance graphite for the true application – oxygen reduction reaction. The main conclusions are that: a) the electrode coverage increased dramatically; b) highly porous 3D structures are formed; c) the polymerized material displays much better catalytic activity and higher selectivity to the desired 4e^-/4H⁺ pathway compared to the monomeric catalyst; and d) the electrode obtained upon electropolymerization on high surface carbon outperforms the industry-standard platinum under alkaline conditions.