Selective Electrochemical Oxygen Reduction to Hydrogen Peroxide by Confinement of Cobalt Porphyrins in a Metal-Organic Framework

Abstract

Sustainable alternatives for the energy intensive synthesis of H₂O₂ are necessary. Molecular cobalt catalysts show potential but are typically restricted by undesired bimolecular pathways leading to the breakdown of both H₂O₂ and the catalyst. The confinement of cobalt porphyrins in the PCN-224 metal-organic framework leads to an enhanced selectivity towards H₂O₂ and stability of the catalyst. Consequently, oxygen can now be selectively reduced to hydrogen peroxide with a stable conversion for at least 5 h, illustrating the potential of catalysts confined in MOFs to increase the selectivity and stability of electrocatalytic conversions.

Keywords: Metal-organic framework; Oxygen-reduction; confinement; electrocatalysis; hydrogen peroxide.